Grizzly Energy (GRZZP) 10-Q 3 May 16 2016 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2016	May. 02, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	Vanguard Natural Resources, LLC
Entity Central Index Key	1,384,072
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		130,981,348

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Revenues:
Oil sales	$ 35,654	$ 35,790
Natural gas sales	36,871	55,754
NGLs sales	8,915	7,350
Net gains on commodity derivative contracts	31,759	59,033
Total revenues	113,199	157,927
Production:
Lease operating expenses	42,328	35,478
Production and other taxes	8,668	11,426
Depreciation, depletion, amortization, and accretion	48,053	66,840
Impairment of oil and natural gas properties	207,764	132,610
Selling, general and administrative expenses	11,021	9,051
Total costs and expenses	317,834	255,405
Loss from operations	(204,635)	(97,478)
Other income (expense):
Interest expense	(25,704)	(20,189)
Net losses on interest rate derivative contracts	(4,691)	(1,203)
Gain on extinguishment of debt	89,714	0
Other	56	40
Total other income (expense), net	59,375	(21,352)
Net loss	(145,260)	(118,830)
Less: Net income attributable to non-controlling interests	(24)	0
Net loss attributable to Vanguard unitholders	(145,284)	(118,830)
Distributions to Preferred unitholders	(6,690)	(6,690)
Net loss attributable to Common and Class B unitholders	$ (151,974)	$ (125,520)
Net loss per Common and Class B unit – basic and diluted (in usd per share)	$ (1.16)	$ (1.49)
Common Units
Other income (expense):
Weighted average Common units outstanding – basic & diluted (in shares)	130,530	83,744
Class B
Other income (expense):
Weighted average Common units outstanding – basic & diluted (in shares)	420	420

CONSOLIDATED BALANCE SHEETS (Un

CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets
Trade accounts receivable, net	$ 92,253	$ 115,200
Derivative assets	216,651	236,886
Other current assets	5,458	6,436
Total current assets	314,362	358,522
Oil and natural gas properties, at cost	4,957,414	4,961,218
Accumulated depletion, amortization and impairment	(3,489,965)	(3,239,242)
Oil and natural gas properties evaluated, net – full cost method	1,467,449	1,721,976
Other assets
Goodwill	506,046	506,046
Derivative assets	55,167	80,161
Other assets	40,541	28,887
Total assets	2,383,565	2,695,592
Accounts payable:
Trade	2,430	22,895
Affiliates	1,392	1,757
Accrued liabilities:
Lease operating	18,161	19,910
Development capital	14,158	26,726
Interest	18,116	11,958
Production and other taxes	43,568	40,472
Other	4,331	10,378
Derivative liabilities	168	356
Oil and natural gas revenue payable	29,231	44,823
Distributions payable	0	5,018
Other	17,206	17,715
Total current liabilities	148,761	202,008
Long-term debt (Note 3)	2,168,995	2,277,931
Asset retirement obligations, net of current portion	261,547	262,432
Other long-term liabilities	39,905	40,656
Total liabilities	$ 2,619,208	$ 2,783,027
Commitments and contingencies (Note 7)
Members’ deficit (Note 8)
Total VNR members’ deficit	$ (242,890)	$ (87,435)
Non-controlling interest in subsidiary	7,247	0
Total members’ deficit	(235,643)	(87,435)
Total liabilities and members’ deficit	2,383,565	2,695,592
Cumulative Preferred Units
Members’ deficit (Note 8)
Total VNR members’ deficit	335,444	335,444
Common Units
Members’ deficit (Note 8)
Total VNR members’ deficit	(585,949)	(430,494)
Class B
Members’ deficit (Note 8)
Total VNR members’ deficit	$ 7,615	$ 7,615

CONSOLIDATED BALANCE SHEETS (U4

CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - shares	Mar. 31, 2016	Dec. 31, 2015
Members’ deficit (Note 8)
Preferred units, issued (shares)	13,881,873	13,881,873
Preferred units, outstanding (shares)	13,881,873	13,881,873
Common Units
Members’ deficit (Note 8)
Common units, issued (shares)	130,966,146	130,476,978
Common units, outstanding (shares)	130,966,146	130,476,978
Class B
Members’ deficit (Note 8)
Common units, issued (shares)	420,000	420,000
Common units, outstanding (shares)	420,000	420,000

CONSOLIDATED STATEMENTS OF MEMB

CONSOLIDATED STATEMENTS OF MEMBERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Non-controlling Interest	Cumulative Preferred UnitsMember Units	Common Units	Common UnitsMember Units	Class BMember Units	EROC Merger [Member]Common Units	EROC Merger [Member]Common UnitsMember Units	LRE Merger [Member]Common Units	LRE Merger [Member]Common UnitsMember Units
Balance at Dec. 31, 2014	$ 1,534,116		$ 335,444		$ 1,191,057	$ 7,615
Increase (Decrease) in Members' Equity [Roll Forward]
Issuance of common units, net of offering costs	35,544				35,544		$ 253,068	$ 253,068	$ 119,315	$ 119,315
Offering costs related to prior period offerings					593					$ 3,961
Repurchase of units under the common unit buyback program	(2,399)				(2,399)
Distributions to Preferred unitholders (see Note 8)	(26,760)				(26,760)
Distributions to Common and Class B unitholders (see Note 8)	(134,019)				(134,019)
Unit-based compensation	16,874				16,874
Net income (loss)	(1,883,174)				(1,883,174)
Balance at Dec. 31, 2015	(87,435)		335,444		(430,494)	7,615
Increase (Decrease) in Members' Equity [Roll Forward]
Offering costs related to prior period offerings				$ 17	17
Distributions to Preferred unitholders (see Note 8)	(5,575)				(5,575)
Distributions to Common and Class B unitholders (see Note 8)	(8,019)				(8,019)
Unit-based compensation	3,440				3,440
Net income (loss)	(145,260)	$ 24			(145,284)
Non-controlling interest in subsidiary	7,453	7,453
Potato Hills cash distribution to non-controlling interest	(230)	(230)
Balance at Mar. 31, 2016	$ (235,643)	$ 7,247	$ 335,444		$ (585,949)	$ 7,615

CONSOLIDATED STATEMENTS OF MEM6

CONSOLIDATED STATEMENTS OF MEMBERS' EQUITY (Unaudited) (Parenthetical) - Common Units - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Offering costs related to prior period offerings	$ (17)
Member Units
Offering costs related to prior period offerings	$ (17)	$ (593)
LRE Merger [Member] | Member Units
Offering costs related to prior period offerings		$ (3,961)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Operating activities
Net loss	$ (145,260)	$ (118,830)	$ (1,883,174)
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion, amortization, and accretion	48,053	66,840
Impairment of oil and natural gas properties	207,764	132,610
Amortization of deferred financing costs	1,117	0
Amortization of debt discount	875	70
Compensation related items	3,440	5,395
Net gains on commodity and interest rate derivative contracts	(27,068)	(57,830)	(169,569)
Cash settlements received on matured commodity derivative contracts	72,617	38,291	211,723
Cash settlements paid on matured interest rate derivative contracts	(2,605)	(990)	(5,227)
Gain on extinguishment of debt	(89,714)	0
Changes in operating assets and liabilities:
Trade accounts receivable	23,097	56,354
Other current assets	353	632
Premiums paid on commodity derivative contracts	1,635	(795)
Accounts payable and oil and natural gas revenue payable	(36,082)	(12,748)
Payable to affiliates	(365)	202
Accrued expenses and other current liabilities	(12,835)	3,345
Other assets	5,139	1,104
Net cash provided by operating activities	50,161	113,650
Investing activities
Additions to property and equipment	(31)	(85)
Potato Hills Gas Gathering System acquisition	(7,471)	0
Additions to oil and natural gas properties	(20,271)	(25,070)
Acquisitions of oil and natural gas properties	(505)	(694)
Deposits and prepayments of oil and natural gas properties	(2,987)	(4)
Proceeds from the sale of oil and natural gas properties	21,114	0
Net cash used in investing activities	(10,151)	(25,853)
Financing activities
Proceeds from long-term debt	78,500	71,500
Repayment of long-term debt	(97,608)	(102,563)
Proceeds from Common unit offerings, net	0	12,213
Repurchase of units under the Common unit buyback program	0	(2,399)
Distributions to Preferred unitholders	(6,690)	(6,690)
Distributions to Common and Class B unitholders	(11,922)	(45,335)
Potato Hills distribution to non-controlling interest	(230)	0
Financing fees	(2,060)	0
Net cash used in financing activities	(40,010)	(73,274)
Net increase cash and cash equivalents	0	14,523
Cash and cash equivalents, beginning of period	0	0	0
Cash and cash equivalents, end of period	0	14,523	$ 0
Supplemental cash flow information:
Cash paid for interest	17,544	19,210
Non-cash financing and investing activity:
Asset retirement obligations, net	$ 3,966	$ 360

Description of the Business

Description of the Business	3 Months Ended
	Mar. 31, 2016
Accounting Policies [Abstract]
Description of Business	Description of the Business: We are a publicly traded limited liability company focused on the acquisition and development of mature, long-lived oil and natural gas properties in the United States. Our primary business objective is to generate stable cash flows allowing us to make monthly cash distributions to our unitholders and, over time, increase our monthly cash distributions through the acquisition of additional mature, long-lived oil and natural gas properties. Through our operating subsidiaries, as of March 31, 2016 , we own properties and oil and natural gas reserves primarily located in ten operating areas: • the Green River Basin in Wyoming; • the Permian Basin in West Texas and New Mexico; • the Gulf Coast Basin in Texas, Louisiana, Mississippi and Alabama; • the Anadarko Basin in Oklahoma and North Texas; • the Piceance Basin in Colorado; • the Big Horn Basin in Wyoming and Montana; • the Arkoma Basin in Arkansas and Oklahoma; • the Williston Basin in North Dakota and Montana; • the Wind River Basin in Wyoming; and • the Powder River Basin in Wyoming. We were formed in October 2006 and completed our initial public offering in October 2007. Our common units are listed on the NASDAQ Global Select Market (“NASDAQ”), an exchange of the NASDAQ OMX Group Inc. (Nasdaq: NDAQ), under the symbol “VNR.” Our Series A, Series B and Series C Cumulative Preferred units are also listed on the NASDAQ under the symbols “VNRAP,” “VNRBP” and “VNRCP,” respectively.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies The accompanying consolidated financial statements are unaudited and were prepared from our records. We derived the Consolidated Balance Sheet as of December 31, 2015 , from the audited financial statements contained in our 2015 Annual Report. Because this is an interim period filing presented using a condensed format, it does not include all of the disclosures required by generally accepted accounting principles in the United States (“GAAP”). You should read this Quarterly Report on Form 10-Q along with our 2015 Annual Report, which contains a summary of our significant accounting policies and other disclosures. In our opinion, we have made all adjustments which are of a normal, recurring nature to fairly present our interim period results. Information for interim periods may not be indicative of our operating results for the entire year. As of March 31, 2016 , our significant accounting policies are consistent with those discussed in Note 1 of our consolidated financial statements contained in our 2015 Annual Report. (a) Basis of Presentation and Principles of Consolidation: The consolidated financial statements as of March 31, 2016 and December 31, 2015 and for the three months ended March 31, 2016 and 2015 include our accounts and those of our subsidiaries. We present our financial statements in accordance with GAAP. All intercompany transactions and balances have been eliminated upon consolidation. Additionally, our financial statements for prior periods include reclassifications that were made to conform to the current period presentation. Those reclassifications did not impact our reported net income (loss) or members’ equity. As of March 31, 2016 , we consolidated Potato Hills Gas Gathering System as we have the ability to control the operating and financial decisions and policies of the entity through our 51% ownership and reflected the non-controlling interest as a separate element in our consolidated financial statements. (b) Oil and Natural Gas Properties: The full cost method of accounting is used to account for oil and natural gas properties. Under the full cost method, substantially all costs incurred in connection with the acquisition, development and exploration of oil, natural gas and NGLs reserves are capitalized. These capitalized amounts include the costs of unproved properties, internal costs directly related to acquisitions, development and exploration activities, asset retirement costs and capitalized interest. Under the full cost method, both dry hole costs and geological and geophysical costs are capitalized into the full cost pool, which is subject to amortization and ceiling test limitations as discussed below. Capitalized costs associated with proved reserves are amortized over the life of the reserves using the unit of production method. Conversely, capitalized costs associated with unproved properties are excluded from the amortizable base until these properties are evaluated, which occurs on a quarterly basis. Specifically, costs are transferred to the amortizable base when properties are determined to have proved reserves. In addition, we transfer unproved property costs to the amortizable base when unproved properties are evaluated as being impaired and as exploratory wells are determined to be unsuccessful. Additionally, the amortizable base includes estimated future development costs, dismantlement, restoration and abandonment costs net of estimated salvage values. Capitalized costs are limited to a ceiling based on the present value of future net revenues, computed using the 12-month unweighted average of first-day-of-the-month historical price, the “12-month average price” discounted at 10% , plus the lower of cost or fair market value of unproved properties. If the ceiling is less than the total capitalized costs, we are required to write-down capitalized costs to the ceiling. We perform this ceiling test calculation each quarter. Any required write-downs are included in the Consolidated Statements of Operations as an impairment charge. We recorded a non-cash ceiling test impairment of oil and natural gas properties for the three months ended March 31, 2016 of $207.8 million as a result of a decline in oil and natural gas prices at the measurement date, March 31, 2016 . The first quarter 2016 impairment was calculated based on the 12-month average price of $2.41 per MMBtu for natural gas and $46.16 per barrel of crude oil. The impairment for the first quarter of 2015 was $132.6 million and was calculated based on the 12-month average price of $3.91 per MMBtu for natural gas and $82.62 per barrel of crude oil. When we sell or convey interests in oil and natural gas properties, we reduce oil and natural gas reserves for the amount attributable to the sold or conveyed interest. We do not recognize a gain or loss on sales of oil and natural gas properties unless those sales would significantly alter the relationship between capitalized costs and proved reserves. Sales proceeds on insignificant sales are treated as an adjustment to the cost of the properties. (c) New Pronouncement Issued But Not Yet Adopted: In August 2015, the FASB issued ASU No. 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date (“ASU No. 2014-14”) to defer the effective date of ASU No. 2014-09 by one year. Public business entities must apply the guidance in ASU 2014-09 to annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. We are evaluating the impact of the pending adoption of ASU No. 2014-09 on our financial position and results of operations and have not yet determined the method by which we will adopt the standard in 2018. In February 2016, the FASB issued ASU No. 2016-02, "Leases (Topic 842)", which requires lessees to recognize at the commencement date for all leases, with the exception of short-term leases, (a) a lease liability, which is a lessee‘s obligation to make lease payments arising from a lease, measured on a discounted basis, and (b) a right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. The ASU on leases will take effect for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. We do not expect the adoption of ASU No. 2016-02 will have a material impact on our consolidated financial statements. In March 2016, the FASB issued ASU No. 2016-05, Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships (“ASU No. 2016-05”). The amendments under ASU No. 2016-05 apply to all reporting entities for which there is a change in the counterparty to a derivative instrument that has been designated as a hedging instrument. The term novation, as it relates to derivative instruments, refers to replacing one of the parties to a derivative instrument with a new party. The derivative instrument that is the subject of a novation may be the hedging instrument in a hedging relationship that has been designated under Topic 815, Derivatives and Hedging. The amendments clarify that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria continue to be met. ASU No. 2016-05 is effective for public business entities for financial statements issued for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. The amendments may be applied on either a prospective basis or a modified retrospective basis. We do not expect the adoption of ASU No. 2016-05 will have a material impact on our consolidated financial statements. In March 2016, the FASB issued ASU No. 2016-09, Compensation -Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting (“ASU No. 2016-09”)that changes the accounting for certain aspects of share-based payments to employees. The new guidance requires excess tax benefits and tax deficiencies to be recorded in the income statement when the awards vest or are settled. In addition, cash flows related to excess tax benefits will no longer be separately classified as a financing activity apart from other income tax cash flows. The standard also allows entities to repurchase more of an employee’s shares for tax withholding purposes without triggering liability accounting, clarifies that all cash payments made on an employee’s behalf for withheld shares should be presented as a financing activity on our cash flows statement, and provides an accounting policy election to account for forfeitures as they occur. For public companies, the amendments are effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. We do not expect the adoption of ASU No. 2016-09 will have a material impact on our consolidated financial statements. (d) Use of Estimates: The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The most significant estimates pertain to proved oil, natural gas and NGLs reserves and related cash flow estimates used in impairment tests of oil and natural gas properties and goodwill, the acquisition of oil and natural gas properties, the fair value of derivative contracts and asset retirement obligations, accrued oil, natural gas and NGLs revenues and expenses, as well as estimates of expenses related to depreciation, depletion, amortization and accretion. Actual results could differ from those estimates. (e) Prior Year Financial Statement Presentation Certain prior year balances have been reclassified to conform to the current year presentation of balances as stated in this quarterly report on Form 10-Q. Please read Note 2—Long-Term Debt for further discussion regarding this reclassification.

Acquisitions and Divestitures

Acquisitions and Divestitures	3 Months Ended
	Mar. 31, 2016
Business Combinations [Abstract]
Acquisitions and Divestitures	2. Acquisitions and Divestitures Our acquisitions are accounted for under the acquisition method of accounting in accordance with ASC Topic 805, “Business Combinations” (“ASC Topic 805”). An acquisition may result in the recognition of a gain or goodwill based on the measurement of the fair value of the assets acquired at the acquisition date as compared to the fair value of consideration transferred, adjusted for purchase price adjustments. Any such gain or any loss resulting from the impairment of goodwill is recognized in current period earnings and classified in other income and expense in the accompanying Consolidated Statements of Operations. The initial accounting for acquisitions may not be complete and adjustments to provisional amounts, or recognition of additional assets acquired or liabilities assumed, may occur as more detailed analyses are completed and additional information is obtained about the facts and circumstances that existed as of the acquisition dates. The results of operations of the properties acquired in our acquisitions have been included in the consolidated financial statements since the closing dates of the acquisitions. All our acquisitions were funded with borrowings under our Reserve-Based Credit Facility (defined in Note 3), except for certain acquisitions, in which the Company issued shares or exchanged assets as described below. 2016 Acquisitions and Divestitures In January 2016, we completed the acquisition of a 51% joint venture interest in Potato Hills Gas Gathering System, a gathering system located in Latimer County, Oklahoma, including the acquisition of the compression assets relating to the gathering system, for a total consideration of $7.7 million . As part of the acquisition, Vanguard also acquired the seller’s rights as manager under the related joint venture agreement. The acquisition was funded with borrowings under our existing Reserve-Based Credit Facility. During the three months ended March 31, 2016, we completed the sale of certain of our properties in Eddy County, New Mexico and Martin County, Texas. Cash proceeds received from the sale of these properties were approximately $21.1 million and were used to reduce borrowings under our Reserve-Based Credit Facility. In March 2016, we entered into a definitive agreement to sell our natural gas, oil and natural gas liquids assets in the SCOOP/STACK area in Oklahoma for $280.0 million , subject to typical purchase price adjustments at closing, to entities managed by Titanium Exploration Partners, LLC (the “SCOOP/STACK Divestiture”). The effective date of the sale is January 1, 2016 and we anticipate closing this acquisition on or before May 18, 2016. Proceeds from the sale will be used to reduce borrowings under our Reserve-Based Credit Facility. 2015 Acquisitions and Mergers On July 31, 2015, we completed the acquisition of additional interests in the same properties located in the Pinedale field of Southwestern Wyoming that were previously acquired in the Pinedale Acquisition in 2014 for an adjusted purchase price of $11.4 million based on an effective date of April 1, 2015. The acquisition was funded with borrowings under our existing Reserve-Based Credit Facility. LRE Merger On October 5, 2015, we completed the transactions contemplated by the Purchase Agreement and Plan of Merger, dated as of April 20, 2015 (the “LRE Merger Agreement”), by and among us, Lighthouse Merger Sub, LLC, our wholly owned subsidiary (“LRE Merger Sub”), Lime Rock Management LP (“LR Management”), Lime Rock Resources A, L.P. (“LRR A”), Lime Rock Resources B, L.P. (“LRR B”), Lime Rock Resources C, L.P. (“LRR C”), Lime Rock Resources II-A, L.P. (“LRR II-A”), Lime Rock Resources II-C, L.P. (“LRR II-C”), and, together with LRR A, LRR B, LRR C, LRR II-A and LR Management, the “GP Sellers”), LRR Energy, L.P. (“LRE”) and LRE GP, LLC (“LRE GP”), the general partner of LRE. Pursuant to the terms of the LRE Merger Agreement, LRE Merger Sub was merged with and into LRE, with LRE continuing as the surviving entity and as our wholly owned subsidiary (the “LRE Merger”), and, at the same time, we acquired all of the limited liability company interests in LRE GP from the GP Sellers in exchange for common units representing limited liability company interests in Vanguard. Under the terms of the LRE Merger Agreement, each common unit representing interests in LRE (the “LRE Common Units”) was converted into the right to receive 0.550 newly issued Vanguard common units. As consideration for the LRE Merger, we issued approximately 15.4 million Vanguard common units valued at $123.3 million based on the closing price per Vanguard common unit of $7.98 at October 5, 2015 and assumed $290.0 million in debt. The debt assumed was extinguished using borrowings under the Company’s Reserve-Based Credit Facility following the close of the LRE Merger. As consideration for our purchase of the limited liability company interests in LRE GP, we issued 12,320 Vanguard common units. The LRE Merger was completed following approval, at a Special Meeting of LRE unitholders on October 5, 2015, of the LRE Merger Agreement and the LRE Merger by holders of a majority of the outstanding LRE Common Units. The following presents the values assigned to the net assets acquired in the LRE Merger as of the merger date (in thousands): Consideration Market value of Vanguard’s common units issued to LRE unitholders $ 123,276 Long-term debt assumed 290,000 413,276 Add: fair value of liabilities assumed Accounts payable and accrued liabilities 5,606 Other current liabilities 9,018 Asset retirement obligations 39,595 Amount attributable to liabilities assumed 54,219 Less: fair value of assets acquired Cash 11,532 Trade accounts receivable 6,822 Other current assets 4,172 Oil and natural gas properties 209,463 Derivative assets 78,725 Other assets 267 Amount attributable assets acquired 310,981 Goodwill $ 156,514 Eagle Rock Merger On October 8, 2015, we completed the transactions contemplated by the Agreement and Plan of Merger, dated as of May 21, 2015 (the “Eagle Rock Merger Agreement”), by and among us, Talon Merger Sub, LLC, our wholly owned subsidiary (“Eagle Rock Merger Sub”), Eagle Rock Energy Partners, L.P. (“Eagle Rock”) and Eagle Rock Energy GP, L.P. (“Eagle Rock GP”). Pursuant to the terms of the Eagle Rock Merger Agreement, Eagle Rock Merger Sub was merged with and into Eagle Rock with Eagle Rock continuing as the surviving entity and as our wholly owned subsidiary (the “Eagle Rock Merger”). Under the terms of the Eagle Rock Merger Agreement, each common unit representing limited partner interests in Eagle Rock (“Eagle Rock Common Unit”) was converted into the right to receive 0.185 newly issued Vanguard common units or, in the case of fractional Vanguard common units, cash (without interest and rounded up to the nearest whole cent). As consideration for the Eagle Rock Merger, Vanguard issued approximately 27.7 million Vanguard common units valued at $258.3 million based on the closing price per Vanguard common unit of $9.31 at October 8, 2015 and assumed $156.6 million in debt. The Company extinguished $122.3 million of the debt assumed using borrowings under its Reserve-Based Credit Facility following the close of Eagle Rock Merger. The Eagle Rock Merger was completed following (i) approval by holders of a majority of the outstanding Eagle Rock Common Units, at a Special Meeting of Eagle Rock unitholders on October 5, 2015, of the Eagle Rock Merger Agreement and the Eagle Rock Merger and (ii) approval by Vanguard unitholders, at Vanguard’s 2015 Annual Meeting of Unitholders, of the issuance of Vanguard common units to be issued as Eagle Rock Merger consideration to the holders of Eagle Rock Common Units in connection with the Eagle Rock Merger. The following presents the values assigned to the net assets acquired in the Eagle Rock Merger as of the merger date (in thousands): Consideration Market value of Vanguard’s common units issued to Eagle Rock unitholders $ 258,282 Long-term debt assumed 156,550 Replacement unit-based payment awards attributable to pre-combination services 346 415,178 Add: fair value of liabilities assumed Accounts payable and accrued liabilities 53,255 Other current liabilities 2,206 Derivative liabilities 2,201 Asset retirement obligations 48,633 Deferred tax liability 39,327 Other long-term liabilities 1,244 Amount attributable to liabilities assumed 146,866 Less: fair value of assets acquired Cash 6,971 Trade accounts receivable 17,543 Other current assets 15,664 Oil and natural gas properties 462,715 Derivative assets 90,234 Other assets 9,734 Amount attributable assets acquired 602,861 Bargain Purchase Gain $ (40,817 ) As a result of the consideration transferred being less than the fair value of net assets acquired, Vanguard reassessed whether it had fully identified all of the assets and liabilities obtained in the acquisition. As part of its reassessment, Vanguard also reevaluated the consideration transferred and whether there were any non-controlling interests in the acquired property. No additional assets or liabilities were identified. Vanguard also determined that there were no non-controlling interests in the Eagle Rock Merger. Vanguard determined that the bargain purchase gain was primarily attributable to unfavorable market trends between the date the parties agreed to the consideration for the Eagle Rock Merger and the date the transaction was completed, resulting in the decline of Vanguard’s unit price. Although the depressed oil and natural gas market also affected the fair value of Eagle Rock’s oil and natural gas properties, it had a more significant impact on Vanguard’s unit price compared to the resulting decrease in the fair value of those properties. As a result, the fair value of the net assets acquired in the Eagle Rock Merger, including the oil and natural gas properties, exceeded the total consideration paid. Pro Forma Operating Results In accordance with ASC Topic 805, presented below are unaudited pro forma results for the three months ended March 31, 2015 to show the effect on our consolidated results of operations as if our acquisitions and mergers completed in 2015 had occurred on January 1, 2014 . The pro forma results reflect the results of combining our statement of operations with the results of operations from the oil and natural gas properties acquired during 2015 , adjusted for (i) the assumption of asset retirement obligations and accretion expense for the properties acquired, (ii) depletion expense applied to the adjusted basis of the properties acquired, (iii) interest expense on additional debt assumed in the LRE and Eagle Rock Mergers, and (iv) the impact of the common units issued in the LRE and Eagle Rock Mergers. The pro forma information is based upon these assumptions and is not necessarily indicative of future results of operations: Pro forma Three Months Ended March 31, 2015 (in thousands, except per unit data) Total revenues $ 246,252 Net loss $ (197,992 ) Net loss per unit Common and Class B units - basic and diluted $ (1.55 ) Post-Acquisition Operating Results The amount of revenues and excess of revenues over direct operating expenses included in the accompanying Consolidated Statements of Operations for our 2015 acquisitions are shown in the table that follows. Direct operating expenses include lease operating expenses, selling, general and administrative expenses and production and other taxes. Three Months Ended March 31, 2016 (in thousands) Eagle Rock Merger Revenues $ 18,972 Excess of revenues over direct operating expenses $ 10,541 LRE Merger Revenues $ 4,540 Excess of revenues over direct operating expenses $ 1,492

Long-Term Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2016
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt Our financing arrangements consisted of the following as of the date indicated: Amount Outstanding Description Interest Rate Maturity Date March 31, 2016 December 31, 2015 (in thousands) Senior Secured Reserve-Based Credit Facility Variable (1) April 16, 2018 $ 1,670,000 $ 1,688,000 Senior Notes due 2019 8.375% (2) June 1, 2019 51,120 51,120 Senior Notes due 2020 7.875% (3) April 1, 2020 381,830 550,000 Senior Notes due 2023 7.00% February 15, 2023 75,634 — Lease Financing Obligation 4.16% August 10, 2020 (4) 23,560 24,668 $ 2,202,144 $ 2,313,788 Less: Unamortized discount on Senior Notes (16,038 ) (17,651 ) Unamortized deferred financing costs (5) (12,563 ) (13,705 ) Current portion of Lease Financing Obligation (4,548 ) (4,501 ) Total long-term debt $ 2,168,995 $ 2,277,931 (1) Variable interest rate was 2.94% and 2.90% at March 31, 2016 and December 31, 2015 , respectively. (2) Effective interest rate was 21.45% . (3) Effective interest rate was 8.00% . (4) The Lease Financing Obligations expire on August 10, 2020, except for certain obligations which expire on July 10, 2021. (5) In order to comply with Accounting Standards Update No. 2015-03, unamortized debt issuance costs have been reclassified from other assets to long-term debt on a retrospective basis. This reclassification had no impact on historical income from continuing operations or members’ equity. Senior Secured Reserve-Based Credit Facility The Company’s Third Amended and Restated Credit Agreement (the “Credit Agreement”) provides a maximum credit facility of $3.5 billion and a borrowing base of $1.78 billion (the “Reserve-Based Credit Facility”). As of March 31, 2016 , there were approximately $1.67 billion of outstanding borrowings and $106.6 million of borrowing capacity under the Reserve-Based Credit Facility, after consideration of a $4.5 million reduction in availability for letters of credit (discussed below). Interest rates under the Reserve-Based Credit Facility are based on Eurodollar (LIBOR) or ABR (Prime) indications, plus a margin. Interest is generally payable quarterly for ABR loans and at the applicable maturity date for LIBOR loans. At March 31, 2016 , the applicable margin and other fees increase as the utilization of the borrowing base increases as follows: Borrowing Base Utilization Grid Borrowing Base Utilization Percentage <25% > 25% <50% > 50% <75% > 75% <90% > 90% Eurodollar Loans Margin 1.50 % 1.75 % 2.00 % 2.25 % 2.50 % ABR Loans Margin 0.50 % 0.75 % 1.00 % 1.25 % 1.50 % Commitment Fee Rate 0.50 % 0.50 % 0.375 % 0.375 % 0.375 % Letter of Credit Fee 0.50 % 0.75 % 1.00 % 1.25 % 1.50 % Our Reserve-Based Credit Facility contains a number of customary covenants that require us to maintain certain financial ratios. Specifically, as of the end of each fiscal quarter, we may not permit the following: (a) our current ratio to be less than 1.0 to 1.0 and (b) our total leverage ratio to be more than 5.25 to 1.0 in 2016 and 4.5 to 1.0 starting in 2017 and beyond. In addition, we are subject to various other covenants including, but not limited to, those limiting our ability to incur indebtedness, enter into commodity and interest rate derivatives, grant certain liens, make certain loans, acquisitions, capital expenditures and investments, merge or consolidate, or engage in certain asset dispositions, including a sale of all or substantially all of our assets. At March 31, 2016 , we were in compliance with all of our debt covenants. We are currently in the process of our semi-annual borrowing base redetermination and anticipate its completion in May 2016. Based on projected market conditions, continued declines in oil and natural gas prices and recent conversations with our administrative agent, we expect that our borrowing base will be redetermined to a level below our outstanding borrowings in our May 2016 redetermination causing a small deficiency. In the case of a borrowing base deficiency, our Reserve-Based Credit facility requires us to repay the deficiency in equal monthly installments over a six month period. Letters of Credit At March 31, 2016 , we have unused irrevocable standby letters of credit of approximately $4.5 million . The letters are being maintained as security for performance on long-term transportation contracts. Borrowing availability for the letters of credit is provided under our Reserve-Based Credit Facility. The fair value of these letters of credit approximates contract values based on the nature of the fee arrangements with the issuing banks. 8.375% Senior Notes Due 2019 At March 31, 2016 , we had $51.1 million outstanding in aggregate principal amount of 8.375% senior notes due in 2019 (the “Senior Notes due 2019”). The Senior Notes due 2019 were assumed by VO in connection with the Eagle Rock Merger. Interest on the Senior Notes due 2019 is payable on June 1 and December 1 of each year. The Senior Notes due 2019 are fully and unconditionally (except for customary release provisions) and jointly and severally guaranteed on a senior unsecured basis by Vanguard and all of our existing subsidiaries, all of which are 100% owned, and certain of our future subsidiaries (the “Subsidiary Guarantors”). We have the option to redeem some or all of the Senior Notes due 2019 at any time at redemption prices equal to the aggregate principal amount multiplied by (i) 102.094% if such Senior Notes due 2019 are redeemed in 2016 and (ii) 100.000% if such Senior Notes due 2019 are redeemed in 2017 and thereafter. 7.875% Senior Notes Due 2020 At March 31, 2016 , we had $381.8 million outstanding in aggregate principal amount of 7.875% senior notes due in 2020 (the “Senior Notes due 2020”). The issuers of the Senior Notes due 2020 are VNR and our 100% owned finance subsidiary, VNRF. VNR has no independent assets or operations. Under the indenture governing the Senior Notes due 2020 (the “Senior Notes Indenture”), our Subsidiary Guarantors (other than VNRF) have unconditionally guaranteed, jointly and severally, on an unsecured basis, the Senior Notes due 2020, subject to release under certain of the following circumstances: (i) upon the sale or other disposition of all or substantially all of the subsidiary’s properties or assets, (ii) upon the sale or other disposition of our equity interests in the subsidiary, (iii) upon designation of the subsidiary as an unrestricted subsidiary in accordance with the terms of the Senior Notes Indenture, (iv) upon legal defeasance or covenant defeasance or the discharge of the Senior Notes Indenture, (v) upon the liquidation or dissolution of the subsidiary; (vi) upon the subsidiary ceasing to guarantee any other of our indebtedness and to be an obligor under any of our credit facilities, or (vii) upon such subsidiary dissolving or ceasing to exist after consolidating with, merging into or transferring all of its properties or assets to us. The Senior Notes Indenture also contains covenants that will limit our ability to (i) incur, assume or guarantee additional indebtedness or issue preferred units; (ii) create liens to secure indebtedness; (iii) make distributions on, purchase or redeem our common units or purchase or redeem subordinated indebtedness; (iv) make investments; (v) restrict dividends, loans or other asset transfers from our restricted subsidiaries; (vi) consolidate with or merge with or into, or sell substantially all of our properties to, another person; (vii) sell or otherwise dispose of assets, including equity interests in subsidiaries; (viii) enter into transactions with affiliates; or (ix) create unrestricted subsidiaries. These covenants are subject to important exceptions and qualifications. If the Senior Notes due 2020 achieve an investment grade rating from each of Standard & Poor’s Rating Services and Moody’s Investors Services, Inc. and no default under the Senior Notes Indenture exists, many of the foregoing covenants will terminate. At March 31, 2016 , based on the most restrictive covenants of the Senior Notes Indenture, our cash balance and the borrowings available under the Reserve-Based Credit Facility, $57.0 million of members’ equity is available for distributions to unitholders, while the remainder is restricted. Interest on the Senior Notes due 2020 is payable on April 1 and October 1 of each year. We may redeem some or all of the Senior Notes due 2020 at any one or more occasions on or after April 1, 2016 at redemption prices of 103.93750% of the aggregate principal amount of the Senior Notes due 2020 as of April 1, 2016, plus accrued and unpaid interest, if any, on the Senior Notes due 2020 redeemed, declining to 100% on April 1, 2018 and thereafter. We had the option to redeem some or all of the Senior Notes due 2020 at any one or more occasions prior to April 1, 2016 at a redemption price equal to 100% of the aggregate principal amount of the Senior Notes due 2020 thereof, plus a “make-whole” premium, and accrued and unpaid interest to the redemption date. We did not redeem any of the Senior Notes due 2020 prior to April 1, 2016. If we sell certain of our assets or experience certain changes of control, we may be required to repurchase all or a portion of the Senior Notes due 2020 at a price equal to 100% and 101% of the aggregate principal amount of the Senior Notes due 2020, respectively. 7.0% Senior Secured Second Lien Notes Due 2023 On February 10, 2016, we issued approximately $75.6 million aggregate principal amount of new 7.0% Senior Secured Second Lien Notes due 2023 (the “Senior Secured Second Lien Notes”) to certain eligible holders of our outstanding 7.875% Senior Notes due 2020 in exchange for approximately $168.2 million aggregate principal amount of the Senior Notes due 2020 held by such holders. Interest on the Senior Secured Second Lien Notes is payable on February 15 and August 15 of each year, beginning on August 15, 2016. The Senior Secured Second Lien Notes will mature on (i) February 15, 2023 or (ii) December 31, 2019 if, prior to December 31, 2019, we have not repurchased, redeemed or otherwise repaid in full all of the Senior Notes due 2020 outstanding at that time in excess of $50.0 million in aggregate principal amount and, to the extent we repurchased, redeemed or otherwise repaid the Senior Notes due 2020 with proceeds of certain indebtedness, if such indebtedness has a final maturity date no earlier than the date that is 91 days after February 15, 2023. Under the indenture governing the Senior Secured Second Lien Notes (the “Senior Secured Second Lien Notes Indenture”), the Subsidiary Guarantors (other than VNRF) have unconditionally guaranteed, jointly and severally, the Senior Secured Second Lien Notes, subject to release under certain of the following circumstances: (i) upon the sale or other disposition of all or substantially all of the subsidiary’s properties or assets, (ii) upon the sale or other disposition of our equity interests in the subsidiary, (iii) upon designation of the subsidiary as an unrestricted subsidiary in accordance with the terms of the Senior Secured Second Lien Indenture, (iv) upon legal defeasance or covenant defeasance or the discharge of the Senior Secured Second Lien Notes Indenture, (v) upon the liquidation or dissolution of the subsidiary; (vi) upon the subsidiary ceasing to guarantee any other of our indebtedness and to be an obligor under any of our credit facilities, or (vii) upon such subsidiary dissolving or ceasing to exist after consolidating with, merging into or transferring all of its properties or assets to us. The Senior Secured Second Lien Notes Indenture also contains covenants that will limit our ability to (i) incur, assume or guarantee additional indebtedness or issue preferred units; (ii) create liens to secure indebtedness; (iii) make distributions on, purchase or redeem our common units or purchase or redeem subordinated indebtedness; (iv) make investments; (v) restrict dividends, loans or other asset transfers from our restricted subsidiaries; (vi) consolidate with or merge with or into, or sell substantially all of our properties to, another person; (vii) sell or otherwise dispose of assets, including equity interests in subsidiaries; (viii) enter into transactions with affiliates; or (ix) create unrestricted subsidiaries. These covenants are subject to important exceptions and qualifications. If the Senior Secured Second Lien Notes achieve an investment grade rating from each of Standard & Poor’s Rating Services and Moody’s Investors Services, Inc. and no default under the Senior Secured Second Lien Notes Indenture exists, many of the foregoing covenants will terminate. At March 31, 2016 , based on the most restrictive covenants of the Senior Secured Second Lien Notes Indenture, our cash balance and the borrowings available under the Reserve-Based Credit Facility, $57.0 million of members’ equity is available for distributions to unitholders, while the remainder is restricted. The exchanges were accounted for as an extinguishment of debt. As a result, we recorded a gain on extinguishment of debt of $89.7 million for the three months ended March 31, 2016 , which is the difference between the aggregate fair market value of the Senior Secured Second Lien Notes issued and the carrying amount of Senior Notes due 2020 extinguished in the exchange, net of unamortized bond discount and deferred financing costs, of $165.3 million . Lease Financing Obligations On October 24, 2014, as part of our acquisition of certain natural gas, oil and NGLs assets in the Piceance Basin (the “Piceance Acquisition”), we entered into an assignment and assumption agreement with Bank of America Leasing & Capital, LLC as the lead bank, whereby we acquired compressors and related facilities and assumed the related financing obligations (the “Lease Financing Obligations”). Certain rights, title, interest and obligations under the Lease Financing Obligations have been assigned to several lenders and are covered by separate assignment agreements, which expire on August 10, 2020 and July 10, 2021. We have the option to purchase the equipment at the end of the lease term for the current fair market value. The Lease Financing Obligations also contain an early buyout option whereby the Company may purchase the equipment for $16.0 million on February 10, 2019. The lease payments related to the equipment are recognized as principal and interest expense based on a weighted average implicit interest rate of 4.16% .

Price and Interest Rate Risk Ma

Price and Interest Rate Risk Management Activities	3 Months Ended
	Mar. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Price and Interest Rate Risk Management Activities	Price and Interest Rate Risk Management Activities We have entered into derivative contracts primarily with counterparties that are also lenders under our Reserve-Based Credit Facility to hedge price risk associated with a portion of our oil, natural gas and NGLs production. While it is never management’s intention to hold or issue derivative instruments for speculative trading purposes, conditions sometimes arise where actual production is less than estimated which has, and could, result in overhedged volumes. Pricing for these derivative contracts is based on certain market indexes and prices at our primary sales points. We also enter into fixed LIBOR interest rate swap agreements with certain counterparties that are lenders under our Reserve-Based Credit Facility, which require exchanges of cash flows that serve to synthetically convert a portion of our variable interest rate obligations to fixed interest rates. At March 31, 2016 , the Company had open commodity derivative contracts covering our anticipated future production as follows: Fixed-Price Swaps (NYMEX) Gas Oil NGLs Contract Period MMBtu Weighted Average Fixed Price Bbls Weighted Average WTI Price Bbls Weighted Average April 1, 2016 – December 31, 2016 54,635,416 $ 4.36 1,406,822 $ 84.01 680,950 $ 30.31 January 1, 2017 – December 31, 2017 40,912,760 $ 3.95 749,698 $ 85.70 — $ — Fixed-Price Swaps (Light Louisiana Sweet) Oil Contract Period Bbls Weighted Average Fixed Price January 1, 2017 – December 31, 2017 168,000 $ 91.25 Call Options Sold Gas Oil Contract Period MMBtu Weighted Average Fixed Price Bbls Weighted Average Fixed Price April 1, 2016 – December 31, 2016 6,875,000 $ 4.25 467,500 $ 50.00 January 1, 2017 – December 31, 2017 9,125,000 $ 3.00 365,000 $ 95.00 Swaptions Gas Contract Period MMBtu Weighted Average Fixed Price January 1, 2017 – December 31, 2017 2,062,500 $ 2.74 January 1, 2018 – December 31, 2018 675,000 $ 2.74 Basis Swaps Gas Contract Period MMBtu Weighted Avg. Basis Differential ($/MMBtu) Pricing Index April 1, 2016 – December 31, 2016 28,875,000 $ (0.20 ) Northwest Rocky Mountain Pipeline and NYMEX Henry Hub Basis Differential January 1, 2017 – December 31, 2017 10,950,000 $ (0.22 ) Northwest Rocky Mountain Pipeline and NYMEX Henry Hub Basis Differential April 1, 2016 – December 31, 2016 726,084 $ (0.08 ) Houston Ship Channel and NYMEX Henry Hub Basis Differential April 1, 2016 – December 31, 2016 212,602 $ (0.10 ) TexOk and NYMEX Henry Hub Basis Differential April 1, 2016 – December 31, 2016 1,194,818 $ (0.13 ) WAHA and NYMEX Henry Hub Basis Differential Oil Contract Period Bbls Weighted Avg. Basis Differential ($/Bbl) Pricing Index April 1, 2016 – December 31, 2016 727,350 $ (1.01 ) WTI Midland and WTI Cushing Basis Differential April 1, 2016 – December 31, 2016 165,000 $ (0.43 ) West Texas Sour and WTI Cushing Basis Differential April 1, 2016 – December 31, 2016 550,000 $ (14.25 ) WTI and West Canadian Select Basis Differential Three-Way Collars Gas Contract Period MMBtu Floor Ceiling Put Sold April 1, 2016 – December 31, 2016 9,625,000 $ 3.95 $ 4.25 $ 3.00 January 1, 2017 – December 31, 2017 16,425,000 $ 3.92 $ 4.23 $ 3.37 Oil Contract Period Bbls Floor Ceiling Put Sold April 1, 2016 – December 31, 2016 797,500 $ 90.00 $ 96.18 $ 73.62 Put Options Sold Gas Oil Contract Period MMBtu Put Sold ($/MMBtu) Bbls Put Sold ($/Bbl) April 1, 2016 – December 31, 2016 1,375,000 $ 3.00 110,000 $ 75.00 January 1, 2017 – December 31, 2017 1,825,000 $ 3.50 73,000 $ 75.00 Range Bonus Accumulators Oil Contract Period Bbls Bonus Range Ceiling Range Floor April 1, 2016 – December 31, 2016 137,500 $ 4.00 $ 100.00 $ 75.00 Collars Oil Contract Period Bbls Floor Price ($/Bbl) Ceiling Price ($/Bbl) April 1, 2016 – December 31, 2016 366,000 $ 38.00 $ 47.25 Puts Oil Contract Period Bbls Put Price ($/Bbl) April 1, 2016 – December 31, 2016 275,000 $ 60.00 Interest Rate Swaps At March 31, 2016 , we had open interest rate derivative contracts as follows (in thousands): Period Notional Amount Fixed LIBOR Rates April 1, 2016 to December 10, 2016 $ 20,000 2.17 % April 1, 2016 to October 31, 2016 $ 40,000 1.65 % April 1, 2016 to August 5, 2018 $ 30,000 2.25 % April 1, 2016 to August 6, 2016 $ 25,000 1.80 % April 1, 2016 to October 31, 2016 $ 20,000 1.78 % April 1, 2016 to September 23, 2016 $ 75,000 1.15 % April 1, 2016 to September 7, 2016 $ 25,000 1.25 % April 1, 2016 to December 31, 2019 $ 175,000 2.32 % April 1, 2016 to February 16, 2017 $ 75,000 1.73 % April 1, 2016 to June 16, 2017 $ 70,000 1.43 % April 1, 2016 to February 16, 2017 $ 75,000 1.73 % Total $ 630,000 Balance Sheet Presentation Our commodity derivatives and interest rate swap derivatives are presented on a net basis in “derivative assets” and “derivative liabilities” on the Consolidated Balance Sheets as governed by the International Swaps and Derivatives Association Master Agreement with each of the counterparties. The following table summarizes the gross fair values of our derivative instruments, presenting the impact of offsetting the derivative assets and liabilities on our Consolidated Balance Sheets for the periods indicated (in thousands): March 31, 2016 Offsetting Derivative Assets: Gross Amounts of Recognized Assets Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets Commodity price derivative contracts $ 305,292 $ (20,901 ) $ 284,391 Interest rate derivative contracts — (12,573 ) (12,573 ) Total derivative instruments $ 305,292 $ (33,474 ) $ 271,818 Offsetting Derivative Liabilities: Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets Commodity price derivative contracts $ (20,900 ) $ 20,900 $ — Interest rate derivative contracts (12,742 ) 12,574 (168 ) Total derivative instruments $ (33,642 ) $ 33,474 $ (168 ) December 31, 2015 Offsetting Derivative Assets: Gross Amounts of Recognized Assets Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets Commodity price derivative contracts $ 349,281 $ (21,834 ) $ 327,447 Interest rate derivative contracts — (10,400 ) (10,400 ) Total derivative instruments $ 349,281 $ (32,234 ) $ 317,047 Offsetting Derivative Liabilities: Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets Commodity price derivative contracts $ (21,934 ) $ 21,834 $ (100 ) Interest rate derivative contracts (10,656 ) 10,400 (256 ) Total derivative instruments $ (32,590 ) $ 32,234 $ (356 ) By using derivative instruments to economically hedge exposures to changes in commodity prices and interest rates, we expose ourselves to credit risk and market risk. Credit risk is the failure of the counterparty to perform under the terms of the derivative contract. When the fair value of a derivative contract is positive, the counterparty owes us, which creates credit risk. The majority of our counterparties are participants in our Reserve-Based Credit Facility (see Note 3. Long-Term Debt for further discussion), which is secured by our oil and natural gas properties; therefore, we are not required to post any collateral. The maximum amount of loss due to credit risk that we would incur if our counterparties failed completely to perform according to the terms of the contracts, based on the gross fair value of financial instruments, was approximately $305.3 million at March 31, 2016 . In accordance with our standard practice, our commodity and interest rate swap derivatives are subject to counterparty netting under agreements governing such derivatives and therefore the risk of such loss is somewhat mitigated as of March 31, 2016 . We minimize the credit risk in derivative instruments by: (i) entering into derivative instruments primarily with counterparties that are also lenders in our Reserve-Based Credit Facility and (ii) monitoring the creditworthiness of our counterparties on an ongoing basis. Changes in fair value of our commodity and interest rate derivatives for the three months ended March 31, 2016 and the year ended December 31, 2015 are as follows: Three Months Ended March 31, 2016 Year Ended December 31, 2015 (in thousands) Derivative asset at beginning of period, net $ 316,691 $ 220,734 Purchases Fair value of derivatives acquired — 195,273 Premiums and fees paid or deferred for derivative contracts (2,097 ) 7,126 Net gains on commodity and interest rate derivative contracts 27,068 169,569 Settlements Cash settlements received on matured commodity derivative contracts (72,617 ) (211,723 ) Cash settlements paid on matured interest rate derivative contracts 2,605 5,227 Termination of derivative contracts — (69,515 ) Derivative asset at end of period, net $ 271,650 $ 316,691

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements We estimate the fair values of financial and non-financial assets and liabilities under ASC Topic 820 “Fair Value Measurements and Disclosures” (“ASC Topic 820”). ASC Topic 820 provides a framework for consistent measurement of fair value for those assets and liabilities already measured at fair value under other accounting pronouncements. Certain specific fair value measurements, such as those related to share-based compensation, are not included in the scope of ASC Topic 820. Primarily, ASC Topic 820 is applicable to assets and liabilities related to financial instruments, to some long-term investments and liabilities, to initial valuations of assets and liabilities acquired in a business combination, recognition of asset retirement obligations and to long-lived assets written down to fair value when they are impaired. It does not apply to oil and natural gas properties accounted for under the full cost method, which are subject to impairment based on SEC rules. ASC Topic 820 applies to assets and liabilities carried at fair value on the Consolidated Balance Sheets, as well as to supplemental information about the fair values of financial instruments not carried at fair value. We have applied the provisions of ASC Topic 820 to assets and liabilities measured at fair value on a recurring basis, which includes our commodity and interest rate derivatives contracts, and on a nonrecurring basis, which includes goodwill, acquisitions of oil and natural gas properties and other intangible assets. ASC Topic 820 provides a definition of fair value and a framework for measuring fair value, as well as expanding disclosures regarding fair value measurements. The framework requires fair value measurement techniques to include all significant assumptions that would be made by willing participants in a market transaction. ASC Topic 820 defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. ASC Topic 820 provides a hierarchy of fair value measurements, based on the inputs to the fair value estimation process. It requires disclosure of fair values classified according to the “levels” described below. The hierarchy is based on the reliability of the inputs used in estimating fair value and requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The framework for fair value measurement assumes that transparent “observable” (Level 1) inputs generally provide the most reliable evidence of fair value and should be used to measure fair value whenever available. The classification of a fair value measurement is determined based on the lowest level (with Level 3 as the lowest) of significant input to the fair value estimation process. The standard describes three levels of inputs that may be used to measure fair value: Level 1 Quoted prices for identical instruments in active markets. Level 2 Quoted market prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations in which all significant inputs and significant value drivers are observable in active markets. Level 3 Valuations derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable. Level 3 assets and liabilities generally include financial instruments whose value is determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation or for which there is a lack of transparency as to the inputs used. As required by ASC Topic 820, financial assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of the fair value of assets and liabilities and their placement within the fair value hierarchy levels. The following methods and assumptions were used to estimate the fair value of each class of financial instruments for which it is practicable to estimate that value: Financing arrangements. The carrying amounts of our bank borrowings outstanding represent their approximate fair value because our current borrowing rates do not materially differ from market rates for similar bank borrowings. We consider this fair value estimate as a Level 2 input. As of March 31, 2016 , the fair value of our Senior Notes due 2020 was estimated to be $55.2 million and our Senior Notes due 2019 was estimated to be $7.3 million . Our Senior Secured Second Lien Notes are a private debt and we estimated its fair value to be $84.1 million valued based on the prices used to estimate the fair value of our Senior Notes due 2020. We consider the inputs to the valuation of our Senior Notes to be Level 1 as fair value was estimated based on prices quoted from a third-party financial institution. Derivative instruments. Our commodity derivative instruments consist of fixed-price swaps, basis swaps, call options sold, swaptions, put options sold, call spreads, call options, put options, three-way collars and range bonus accumulators. We account for our commodity derivatives and interest rate derivatives at fair value on a recurring basis. We estimate the fair values of the fixed-price swaps and basis-swaps based on published forward commodity price curves for the underlying commodities as of the date of the estimate. We estimate the option value of the contract floors, ceilings and three-way collars using an option pricing model which takes into account market volatility, market prices and contract parameters. The discount rate used in the discounted cash flow projections is based on published LIBOR rates, Eurodollar futures rates and interest swap rates. In order to estimate the fair value of our interest rate swaps, we use a yield curve based on money market rates and interest rate swaps, extrapolate a forecast of future interest rates, estimate each future cash flow, derive discount factors to value the fixed and floating rate cash flows of each swap, and then discount to present value all known (fixed) and forecasted (floating) swap cash flows. We consider the fair value estimate for these derivative instruments as a Level 2 input. We estimate the value of the range bonus accumulators using an option pricing model for both Asian Range Digital options and Asian Put options that takes into account market volatility, market prices and contract parameters. Range bonus accumulators are complex in structure requiring sophisticated valuation methods and greater subjectivity. As such, range bonus accumulators valuation may include inputs and assumptions that are less observable or require greater estimation, thereby resulting in valuations with less certainty. We consider the fair value estimate for range bonus accumulators as a Level 3 input. Inputs to the pricing models include publicly available prices and forward price curves generated from a compilation of data gathered from third parties. Management validates the data provided by third parties by understanding the pricing models used, analyzing pricing data in certain situations and confirming that those securities trade in active markets. Assumed credit risk adjustments, based on published credit ratings, public bond yield spreads and credit default swap spreads, are applied to our commodity derivatives and interest rate derivatives. Financial assets and financial liabilities measured at fair value on a recurring basis are summarized below (in thousands): March 31, 2016 Fair Value Measurements Using Assets/Liabilities Level 1 Level 2 Level 3 at Fair value Assets: Commodity price derivative contracts $ — $ 288,800 $ (4,409 ) $ 284,391 Interest rate derivative contracts — (12,573 ) — (12,573 ) Total derivative instruments $ — $ 276,227 $ (4,409 ) $ 271,818 Liabilities: Interest rate derivative contracts $ — $ (168 ) $ — $ (168 ) Total derivative instruments $ — $ (168 ) $ — $ (168 ) December 31, 2015 Fair Value Measurements Using Assets/Liabilities Level 1 Level 2 Level 3 at Fair value Assets: Commodity price derivative contracts $ — $ 333,380 $ (5,933 ) $ 327,447 Interest rate derivative contracts — (10,400 ) — (10,400 ) Total derivative instruments $ — $ 322,980 $ (5,933 ) $ 317,047 Liabilities: Commodity price derivative contracts $ — $ (99 ) $ — $ (99 ) Interest rate derivative contracts — (257 ) — (257 ) Total derivative instruments $ — $ (356 ) $ — $ (356 ) The following table sets forth a reconciliation of changes in the fair value of financial assets and liabilities classified as Level 3 (unobservable inputs) in the fair value hierarchy: Three Months Ended March 31, 2016 2015 (in thousands) Unobservable inputs, beginning of period $ (5,933 ) $ (6,470 ) Total gains 3,412 1,287 Settlements (1,888 ) (1,152 ) Unobservable inputs, end of period $ (4,409 ) $ (6,335 ) Change in fair value included in earnings related to derivatives still held as of March 31, $ (84 ) $ (804 ) During periods of market disruption, including periods of volatile oil and natural gas prices, there may be certain asset classes that were in active markets with observable data that become illiquid due to changes in the financial environment. In such cases, more derivative instruments, other than the range bonus accumulators, may fall to Level 3 and thus require more subjectivity and management judgment. Further, rapidly changing commodity and unprecedented credit and equity market conditions could materially impact the valuation of derivative instruments as reported within our consolidated financial statements and the period-to-period changes in value could vary significantly. Decreases in value may have a material adverse effect on our results of operations or financial condition. We apply the provisions of ASC Topic 350 “ Intangibles-Goodwill and Other .” Goodwill represents the excess of the purchase price over the estimated fair value of the net assets acquired in business combinations. Goodwill is assessed for impairment annually on October 1 or whenever indicators of impairment exist. The goodwill test is performed at the reporting unit level, which represents our oil and natural gas operations in the United States. If indicators of impairment are determined to exist, an impairment charge is recognized if the carrying value of goodwill exceeds its implied fair value. We utilize a market approach to determine the fair value of our reporting unit. While no goodwill impairment was recognized at March 31, 2016 , any further significant decline in prices of oil and natural gas or significant negative reserve adjustments could change our estimate of the fair value of the reporting unit and could result in an impairment charge. Our nonfinancial assets and liabilities that are initially measured at fair value are comprised primarily of assets acquired in business combinations and asset retirement costs and obligations. These assets and liabilities are recorded at fair value when acquired/incurred but not re-measured at fair value in subsequent periods. We classify such initial measurements as Level 3 since certain significant unobservable inputs are utilized in their determination. A reconciliation of the beginning and ending balance of our asset retirement obligations is presented in Note 6, in accordance with ASC Topic 410-20 “ Asset Retirement Obligations. ” During the three months ended March 31, 2016 , in connection with new wells drilled, we incurred and recorded asset retirement obligations totaling $0.1 million , at fair value. During the year ended December 31, 2015 , in connection with the oil and natural gas properties acquired in all of our acquisitions, the LRE and Eagle Rock Mergers, as well as new wells drilled, we incurred and recorded asset retirement obligations totaling $90.9 million , at fair value. In addition, we recorded a $22.3 million change in estimate as a result of revisions to the timing or the amount of our original undiscounted estimated asset retirement costs during the year ended December 31, 2015 . The fair value of additions to the asset retirement obligation liability is measured using valuation techniques consistent with the income approach, converting future cash flows to a single discounted amount. Inputs to the valuation include: (1) estimated plug and abandonment cost per well based on our experience; (2) estimated remaining life per well based on average reserve life per field; (3) our credit-adjusted risk-free interest rate ranging between 4.6% and 5.5% ; and (4) the average inflation factor ( 2.0% ). These inputs require significant judgments and estimates by the Company’s management at the time of the valuation and are the most sensitive and subject to change.

Asset Retirement Obligations

Asset Retirement Obligations	3 Months Ended
	Mar. 31, 2016
Asset Retirement Obligation [Abstract]
Asset Retirement Obligations	Asset Retirement Obligations The asset retirement obligations as of March 31, 2016 and December 31, 2015 reported on our Consolidated Balance Sheets and the changes in the asset retirement obligations for the three months ended March 31, 2016 and the year ended December 31, 2015 were as follows: March 31, 2016 December 31, 2015 (in thousands) Asset retirement obligations, beginning of period $ 271,456 $ 149,062 Liabilities added during the current period 143 2,699 Liabilities added from the LRE and Eagle Rock Mergers — 88,228 Accretion expense 3,113 10,238 Retirements (32 ) (838 ) Liabilities related to assets divested (2,102 ) (262 ) Change in estimate (2,007 ) 22,329 Asset retirement obligation, end of period 270,571 271,456 Less: current obligations (9,024 ) (9,024 ) Long-term asset retirement obligation, end of period $ 261,547 $ 262,432 Each year the Company reviews and, to the extent necessary, revises its asset retirement obligation estimates. During 2015 , the Company reviewed actual abandonment costs with previous estimates and, as a result, increased its estimates of future asset retirement obligations by $22.3 million to reflect increased costs incurred for plugging and abandonment costs.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Transportation Demand Charges As of March 31, 2016 , we have contracts that provide firm transportation capacity on pipeline systems. The remaining terms on these contracts range from three months to four years and require us to pay transportation demand charges regardless of the amount of pipeline capacity we utilize. The values in the table below represent gross future minimum transportation demand charges we are obligated to pay as of March 31, 2016 . However, our financial statements will reflect our proportionate share of the charges based on our working interest and net revenue interest, which will vary from property to property. March 31, 2016 (in thousands) April 1, 2016 - December 31, 2016 $ 10,964 2017 12,512 2018 11,696 2019 9,661 2020 410 Total $ 45,243 Legal Proceedings We are defendants in certain legal proceedings arising in the normal course of our business. While the outcome and impact of such legal proceedings on the Company cannot be predicted with certainty, management does not believe that it is probable that the outcome of these actions will have a material adverse effect on the Company’s consolidated financial position, results of operations or cash flow. In addition, we are not aware of any legal or governmental proceedings against us, or contemplated to be brought against us, under the various environmental protection statutes to which we are subject. We are also a party to separate legal proceedings relating to (i) the LRE Merger, (ii) the Eagle Rock Merger and (iii) the exchange of our new Senior Secured Second Lien Notes for some of the existing Senior Notes due 2020, which closed in February 2016 (please read Note 3. Long-Term Debt for further discussion). Please read Part II, Item 1, Legal Proceedings for further discussion.

Members_ Deficit and Net Loss p

Members’ Deficit and Net Loss per Common and Class B Unit	3 Months Ended
	Mar. 31, 2016
Equity [Abstract]
Members’ Deficit and Net Loss per Common and Class B Unit	Members’ Deficit and Net Loss per Common and Class B Unit Cumulative Preferred Units The following table summarizes the Company’s Cumulative Preferred Units outstanding at March 31, 2016 and December 31, 2015 : March 31, 2016 December 31, 2015 Earliest Redemption Date Liquidation Preference Per Unit Distribution Rate Units Outstanding Carrying Value Units Outstanding Carrying Value Series A June 15, 2023 $25.00 7.875% 2,581,873 $ 62,200 2,581,873 $ 62,200 Series B April 15, 2024 $25.00 7.625% 7,000,000 $ 169,265 7,000,000 $ 169,265 Series C October 15, 2024 $25.00 7.75% 4,300,000 $ 103,979 4,300,000 $ 103,979 Total Cumulative Preferred Units 13,881,873 $ 335,444 13,881,873 $ 335,444 The Series A, B and C Cumulative Preferred Units (collectively the “Cumulative Preferred Units”) have no stated maturity and are not subject to mandatory redemption or any sinking fund and will remain outstanding indefinitely unless repurchased or redeemed by us or converted into our common units, at our option, in connection with a change of control. The Cumulative Preferred Units can be redeemed, in whole or in part, out of amounts legally available therefore, at a redemption price of $25.00 per unit plus an amount equal to all accumulated and unpaid distributions thereon to the date of redemption, whether or not declared. We may also redeem the Cumulative Preferred Units in the event of a change of control. Holders of the Cumulative Preferred Units will have no voting rights except for limited voting rights if we fail to pay dividends for eighteen or more monthly periods (whether or not consecutive) and in certain other limited circumstances or as required by law. The Cumulative Preferred Units have a liquidation preference which is equal to the redemption price described above. On February 25, 2016, our board of directors elected to suspend cash distributions to the holders of our common and Class B units and Cumulative Preferred Units effective with the February 2016 distribution. All preferred distributions will continue to accumulate and must be paid in full before distributions to common and Class B unitholders can resume. As of March 31, 2016 , dividends in arrears related to our Series A, B and C Cumulative Preferred Units were $0.4 million , $1.1 million and $0.7 million , respectively. Common and Class B Units The common units represent limited liability company interests. Holders of Class B units have substantially the same rights and obligations as the holders of common units. The following is a summary of the changes in our common units issued during the three months ended March 31, 2016 and the year ended December 31, 2015 (in thousands): March 31, 2016 December 31, 2015 Beginning of period 130,477 83,452 Issuance of Common units as consideration for the Eagle Rock Merger — 27,886 Issuance of Common units as consideration for the LRE Merger — 15,448 Issuance of Common units for cash — 2,430 Repurchase of units under the Common unit buyback program — (157 ) Unit-based compensation 489 1,418 End of period 130,966 130,477 There was no change in issued and outstanding Class B units during the three months ended March 31, 2016 or the year ended December 31, 2015 . Net Loss per Common and Class B Unit Basic net income per common and Class B unit is computed in accordance with ASC Topic 260 “ Earnings Per Share ” (“ASC Topic 260”) by dividing net income attributable to common and Class B unitholders, which reflects all accumulated distributions on cumulative preferred units, including distributions in arrears, by the weighted average number of units outstanding during the period. Diluted net income per common and Class B unit is computed by adjusting the average number of units outstanding for the dilutive effect, if any, of unit equivalents. We use the treasury stock method to determine the dilutive effect. Class B units participate in distributions; therefore, all Class B units were considered in the computation of basic net income per unit. The Cumulative Preferred Units have no participation rights and accordingly are excluded from the computation of basic net income per unit. For the three months ended March 31, 2016 and 2015 , 2,711,333 and 202,407 phantom units were excluded from the calculation of diluted earnings per unit, respectively, due to their antidilutive effect as we were in a loss position. Distributions Declared The Cumulative Preferred Units rank senior to our common units with respect to the payment of distributions and distribution of assets upon liquidation, dissolution and winding up. Distributions on the Preferred Units are cumulative from the date of original issue and will be payable monthly in arrears on the 15th day of each month of each year, when, as and if declared by our board of directors. Distributions on our Cumulative Preferred Units accumulate at a monthly rate of 7.875% per annum of the liquidation preference of $25.00 per Series A Cumulative Preferred Unit, a monthly rate of 7.625% per annum of the liquidation preference of $25.00 per Series B Cumulative Preferred Unit and a monthly rate of 7.75% per annum of the liquidation preference of $25.00 per Series C Cumulative Preferred Unit. The following table shows the distribution amount per unit, declared date, record date and payment date of the cash distributions we paid on each of our common and Class B units attributable to each period presented. Future distributions are at the discretion of our board of directors and will depend on business conditions, earnings, our cash requirements and other relevant factors. As discussed above, our board of directors elected to suspend cash distributions to the holders of our common and Class B units and Cumulative Preferred Units effective with the February 2016 distribution. Cash Distributions Distribution Per Unit Declared Date Record Date Payment Date 2016 First Quarter January $ 0.0300 February 18, 2016 March 1, 2016 March 15, 2016 2015 Fourth Quarter December $ 0.0300 January 20, 2016 February 1, 2016 February 12, 2016 November $ 0.0300 December 18, 2015 January 4, 2016 January 14, 2016 October $ 0.1175 November 20, 2015 December 1, 2015 December 15, 2015 Third Quarter September $ 0.1175 October 19, 2015 November 2, 2015 November 13, 2015 August $ 0.1175 September 21, 2015 October 1, 2015 October 15, 2015 July $ 0.1175 August 20, 2015 September 1, 2015 September 14, 2015 Second Quarter June $ 0.1175 July 16, 2015 August 3, 2015 August 14, 2015 May $ 0.1175 June 18, 2015 July 1, 2015 July 15, 2015 April $ 0.1175 May 19, 2015 June 1, 2015 June 12, 2015 First Quarter March $ 0.1175 April 15, 2015 May 1, 2015 May 15, 2015 February $ 0.1175 March 18, 2015 April 1, 2015 April 14, 2015 January $ 0.1175 February 17, 2015 March 2, 2015 March 17, 2015 2014 Fourth Quarter December $ 0.2100 January 22, 2015 February 2, 2015 February 13, 2015

Unit-Based Compensation

Unit-Based Compensation	3 Months Ended
	Mar. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Unit-Based Compensation	Unit-Based Compensation Long-Term Incentive Plan The Vanguard Natural Resources, LLC Long-Term Incentive Plan (the “VNR LTIP”) was adopted by the Board of Directors of the Company to compensate employees and nonemployee directors of the Company and its affiliates who perform services for the Company under the terms of the plan. The VNR LTIP is administered by the compensation committee of the board of directors (the “Compensation Committee”) and permits the grant of unrestricted units, restricted units, phantom units, unit options and unit appreciation rights. Restricted and Phantom Units A restricted unit is a unit grant that vests over a period of time and that during such time is subject to forfeiture. A phantom unit grant represents the equivalent of one common unit of the Company. The phantom units, once vested, are settled through the delivery of a number of common units equal to the number of such vested units, or an amount of cash equal to the fair market value of such common units on the vesting date to be paid in a single lump sum payment, as determined by the compensation committee in its discretion. The Compensation Committee may grant tandem distribution equivalent rights (“DERs”) with respect to the phantom units that entitle the holder to receive the value of any distributions made by us on our units while the phantom units are outstanding. The fair value of restricted unit and phantom unit awards is measured based on the fair market value of the Company units on the date of grant. The values of restricted unit grants and phantom unit grants that are required to be settled in units are recognized as expense over the vesting period of the grants with a corresponding charge to members’ equity. When the Company has the option to settle the phantom unit grants by issuing Company units or through cash settlement, the Company recognizes the value of those grants utilizing the liability method as defined under ASC Topic 718 based on the Company’s historical practice of settling phantom units predominantly in cash. The fair value of liability awards is remeasured at each reporting date through the settlement date with the change in fair value recognized as compensation expense over that period. Executive Employment Agreements On March 18, 2016, we and VNRH entered into new amended and restated executive employment agreements (the “Amended Agreements”) with each of our three executive officers, Messrs. Smith, Robert and Pence in order to set forth in writing the revised terms of each executive’s employment relationship with VNRH. The Amended Agreements were effective January 1, 2016 and the initial term of the Amended Agreements ends on January 1, 2019, with a subsequent twelve-month term extension automatically commencing on January 1, 2019 and each successive January 1 thereafter, provided that neither VNRH nor the executives deliver a timely non-renewal notice prior to a term expiration date. The Amended Agreements provide for the executive officers an annual base salary and eligibility to receive an annual performance-based cash bonus award. The annual bonus will be calculated based upon four Company performance components: adjusted EBITDA results, production results, lease operating expenses, and cash general and administrative expenses, as well as a fifth component determined solely in the discretion of our board of directors. As of March 31, 2016 , an accrued liability was recognized and compensation expense of $0.5 million was recorded for the three months ended March 31, 2016 related to these arrangements, which was classified in the selling, general and administrative expenses line item in the Consolidated Statement of Operations. Under the Amended Agreements, the executives are also eligible to receive annual equity-based compensation awards, consisting of restricted units and/or phantom units granted under the VNR LTIP. Any restricted units and phantom units granted to executives under the Amended Agreements are subject to a three-year vesting period. One-third of the aggregate number of the units vest on each one-year anniversary of the date of grant so long as the executive remains continuously employed with the Company. Both the restricted and phantom units include a tandem grant of DERs. 2016 Unit Grants In January 2016, the executives were granted a total of 2,255,033 phantom units in accordance with the Amended Agreements. Also, during the three months ended March 31, 2016 , our three independent board members were granted a total of 125,838 phantom units which will vest one year from the date of grant. A VNR employee was also granted a total of 7,500 restricted units under the VNR LTIP of which one-third will vest on each one-year anniversary of the date of grant so long as the employee remains continuously employed with the Company. The phantom units include a tandem grant of DERs. Restricted Units A summary of the status of the non-vested restricted units as of March 31, 2016 is presented below: Number of Non-vested Restricted Units Weighted Average Grant Date Fair Value Non-vested restricted units at December 31, 2015 976,348 $ 18.29 Granted 7,500 $ 3.11 Forfeited (8,500 ) $ 15.64 Vested (209,708 ) $ 19.37 Non-vested restricted units at March 31, 2016 765,640 $ 17.88 At March 31, 2016 , there was approximately $9.3 million of unrecognized compensation cost related to non-vested restricted units. The cost is expected to be recognized over an average period of approximately 1.7 years. Our Consolidated Statements of Operations reflect non-cash compensation related to restricted unit grants of $1.3 million and $3.5 million in the selling, general and administrative expenses line item for the three months ended March 31, 2016 and 2015 , respectively. Phantom Units A summary of the status of the non-vested phantom units under the VNR LTIP as of March 31, 2016 is presented below: Number of Non-vested Phantom Units Weighted Average Grant Date Fair Value Non-vested restricted units at December 31, 2015 203,221 $ 20.99 Granted 2,380,871 $ 2.98 Forfeited (262 ) $ 19.62 Non-vested phantom units at March 31, 2016 2,583,830 $ 4.39 At March 31, 2016 , there was approximately $8.3 million of unrecognized compensation cost related to non-vested phantom units. The cost is expected to be recognized over an average period of approximately 1.4 years . Our Consolidated Statements of Operations reflect non-cash compensation related to phantom unit grants of $1.1 million and $0.4 million in the selling, general and administrative expense line item for the three months ended March 31, 2016 and 2015 , respectively.

Summary of Significant Accoun18

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation: The consolidated financial statements as of March 31, 2016 and December 31, 2015 and for the three months ended March 31, 2016 and 2015 include our accounts and those of our subsidiaries. We present our financial statements in accordance with GAAP. All intercompany transactions and balances have been eliminated upon consolidation. Additionally, our financial statements for prior periods include reclassifications that were made to conform to the current period presentation. Those reclassifications did not impact our reported net income (loss) or members’ equity. As of March 31, 2016 , we consolidated Potato Hills Gas Gathering System as we have the ability to control the operating and financial decisions and policies of the entity through our 51% ownership and reflected the non-controlling interest as a separate element in our consolidated financial statements.
Oil and Natural Gas Properties	Oil and Natural Gas Properties: The full cost method of accounting is used to account for oil and natural gas properties. Under the full cost method, substantially all costs incurred in connection with the acquisition, development and exploration of oil, natural gas and NGLs reserves are capitalized. These capitalized amounts include the costs of unproved properties, internal costs directly related to acquisitions, development and exploration activities, asset retirement costs and capitalized interest. Under the full cost method, both dry hole costs and geological and geophysical costs are capitalized into the full cost pool, which is subject to amortization and ceiling test limitations as discussed below. Capitalized costs associated with proved reserves are amortized over the life of the reserves using the unit of production method. Conversely, capitalized costs associated with unproved properties are excluded from the amortizable base until these properties are evaluated, which occurs on a quarterly basis. Specifically, costs are transferred to the amortizable base when properties are determined to have proved reserves. In addition, we transfer unproved property costs to the amortizable base when unproved properties are evaluated as being impaired and as exploratory wells are determined to be unsuccessful. Additionally, the amortizable base includes estimated future development costs, dismantlement, restoration and abandonment costs net of estimated salvage values. Capitalized costs are limited to a ceiling based on the present value of future net revenues, computed using the 12-month unweighted average of first-day-of-the-month historical price, the “12-month average price” discounted at 10% , plus the lower of cost or fair market value of unproved properties. If the ceiling is less than the total capitalized costs, we are required to write-down capitalized costs to the ceiling. We perform this ceiling test calculation each quarter. Any required write-downs are included in the Consolidated Statements of Operations as an impairment charge. We recorded a non-cash ceiling test impairment of oil and natural gas properties for the three months ended March 31, 2016 of $207.8 million as a result of a decline in oil and natural gas prices at the measurement date, March 31, 2016 . The first quarter 2016 impairment was calculated based on the 12-month average price of $2.41 per MMBtu for natural gas and $46.16 per barrel of crude oil. The impairment for the first quarter of 2015 was $132.6 million and was calculated based on the 12-month average price of $3.91 per MMBtu for natural gas and $82.62 per barrel of crude oil. When we sell or convey interests in oil and natural gas properties, we reduce oil and natural gas reserves for the amount attributable to the sold or conveyed interest. We do not recognize a gain or loss on sales of oil and natural gas properties unless those sales would significantly alter the relationship between capitalized costs and proved reserves. Sales proceeds on insignificant sales are treated as an adjustment to the cost of the properties.
New Pronouncements Issued But Not Yet Adopted	New Pronouncement Issued But Not Yet Adopted: In August 2015, the FASB issued ASU No. 2015-14, Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date (“ASU No. 2014-14”) to defer the effective date of ASU No. 2014-09 by one year. Public business entities must apply the guidance in ASU 2014-09 to annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. Earlier application is permitted only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. We are evaluating the impact of the pending adoption of ASU No. 2014-09 on our financial position and results of operations and have not yet determined the method by which we will adopt the standard in 2018. In February 2016, the FASB issued ASU No. 2016-02, "Leases (Topic 842)", which requires lessees to recognize at the commencement date for all leases, with the exception of short-term leases, (a) a lease liability, which is a lessee‘s obligation to make lease payments arising from a lease, measured on a discounted basis, and (b) a right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. The ASU on leases will take effect for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. We do not expect the adoption of ASU No. 2016-02 will have a material impact on our consolidated financial statements. In March 2016, the FASB issued ASU No. 2016-05, Effect of Derivative Contract Novations on Existing Hedge Accounting Relationships (“ASU No. 2016-05”). The amendments under ASU No. 2016-05 apply to all reporting entities for which there is a change in the counterparty to a derivative instrument that has been designated as a hedging instrument. The term novation, as it relates to derivative instruments, refers to replacing one of the parties to a derivative instrument with a new party. The derivative instrument that is the subject of a novation may be the hedging instrument in a hedging relationship that has been designated under Topic 815, Derivatives and Hedging. The amendments clarify that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria continue to be met. ASU No. 2016-05 is effective for public business entities for financial statements issued for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. The amendments may be applied on either a prospective basis or a modified retrospective basis. We do not expect the adoption of ASU No. 2016-05 will have a material impact on our consolidated financial statements. In March 2016, the FASB issued ASU No. 2016-09, Compensation -Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting (“ASU No. 2016-09”)that changes the accounting for certain aspects of share-based payments to employees. The new guidance requires excess tax benefits and tax deficiencies to be recorded in the income statement when the awards vest or are settled. In addition, cash flows related to excess tax benefits will no longer be separately classified as a financing activity apart from other income tax cash flows. The standard also allows entities to repurchase more of an employee’s shares for tax withholding purposes without triggering liability accounting, clarifies that all cash payments made on an employee’s behalf for withheld shares should be presented as a financing activity on our cash flows statement, and provides an accounting policy election to account for forfeitures as they occur. For public companies, the amendments are effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. We do not expect the adoption of ASU No. 2016-09 will have a material impact on our consolidated financial statements.
Use of Estimates	Use of Estimates: The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The most significant estimates pertain to proved oil, natural gas and NGLs reserves and related cash flow estimates used in impairment tests of oil and natural gas properties and goodwill, the acquisition of oil and natural gas properties, the fair value of derivative contracts and asset retirement obligations, accrued oil, natural gas and NGLs revenues and expenses, as well as estimates of expenses related to depreciation, depletion, amortization and accretion. Actual results could differ from those estimates.
Prior Year Financial Statement Presentation	Prior Year Financial Statement Presentation Certain prior year balances have been reclassified to conform to the current year presentation of balances as stated in this quarterly report on Form 10-Q. Please read Note 2—Long-Term Debt for further discussion regarding this reclassification.

Acquisitions and Divestitures (

Acquisitions and Divestitures (Tables)	3 Months Ended
	Mar. 31, 2016
Business Acquisition [Line Items]
Fair value of assets and liabilities acquired	Consideration Market value of Vanguard’s common units issued to Eagle Rock unitholders $ 258,282 Long-term debt assumed 156,550 Replacement unit-based payment awards attributable to pre-combination services 346 415,178 Add: fair value of liabilities assumed Accounts payable and accrued liabilities 53,255 Other current liabilities 2,206 Derivative liabilities 2,201 Asset retirement obligations 48,633 Deferred tax liability 39,327 Other long-term liabilities 1,244 Amount attributable to liabilities assumed 146,866 Less: fair value of assets acquired Cash 6,971 Trade accounts receivable 17,543 Other current assets 15,664 Oil and natural gas properties 462,715 Derivative assets 90,234 Other assets 9,734 Amount attributable assets acquired 602,861 Bargain Purchase Gain $ (40,817 )
Pro Forma Information	The pro forma results reflect the results of combining our statement of operations with the results of operations from the oil and natural gas properties acquired during 2015 , adjusted for (i) the assumption of asset retirement obligations and accretion expense for the properties acquired, (ii) depletion expense applied to the adjusted basis of the properties acquired, (iii) interest expense on additional debt assumed in the LRE and Eagle Rock Mergers, and (iv) the impact of the common units issued in the LRE and Eagle Rock Mergers. The pro forma information is based upon these assumptions and is not necessarily indicative of future results of operations: Pro forma Three Months Ended March 31, 2015 (in thousands, except per unit data) Total revenues $ 246,252 Net loss $ (197,992 ) Net loss per unit Common and Class B units - basic and diluted $ (1.55 )
Revenues and Excess of Revenues Over Direct Operating Expenses	The amount of revenues and excess of revenues over direct operating expenses included in the accompanying Consolidated Statements of Operations for our 2015 acquisitions are shown in the table that follows. Direct operating expenses include lease operating expenses, selling, general and administrative expenses and production and other taxes. Three Months Ended March 31, 2016 (in thousands) Eagle Rock Merger Revenues $ 18,972 Excess of revenues over direct operating expenses $ 10,541 LRE Merger Revenues $ 4,540 Excess of revenues over direct operating expenses $ 1,492
LRE Merger [Member]
Business Acquisition [Line Items]
Fair value of assets and liabilities acquired	Consideration Market value of Vanguard’s common units issued to LRE unitholders $ 123,276 Long-term debt assumed 290,000 413,276 Add: fair value of liabilities assumed Accounts payable and accrued liabilities 5,606 Other current liabilities 9,018 Asset retirement obligations 39,595 Amount attributable to liabilities assumed 54,219 Less: fair value of assets acquired Cash 11,532 Trade accounts receivable 6,822 Other current assets 4,172 Oil and natural gas properties 209,463 Derivative assets 78,725 Other assets 267 Amount attributable assets acquired 310,981 Goodwill $ 156,514

Long-Term Debt (Tables)

Long-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2016
Debt Disclosure [Abstract]
Financing Arrangements	Our financing arrangements consisted of the following as of the date indicated: Amount Outstanding Description Interest Rate Maturity Date March 31, 2016 December 31, 2015 (in thousands) Senior Secured Reserve-Based Credit Facility Variable (1) April 16, 2018 $ 1,670,000 $ 1,688,000 Senior Notes due 2019 8.375% (2) June 1, 2019 51,120 51,120 Senior Notes due 2020 7.875% (3) April 1, 2020 381,830 550,000 Senior Notes due 2023 7.00% February 15, 2023 75,634 — Lease Financing Obligation 4.16% August 10, 2020 (4) 23,560 24,668 $ 2,202,144 $ 2,313,788 Less: Unamortized discount on Senior Notes (16,038 ) (17,651 ) Unamortized deferred financing costs (5) (12,563 ) (13,705 ) Current portion of Lease Financing Obligation (4,548 ) (4,501 ) Total long-term debt $ 2,168,995 $ 2,277,931 (1) Variable interest rate was 2.94% and 2.90% at March 31, 2016 and December 31, 2015 , respectively. (2) Effective interest rate was 21.45% . (3) Effective interest rate was 8.00% . (4) The Lease Financing Obligations expire on August 10, 2020, except for certain obligations which expire on July 10, 2021. (5) In order to comply with Accounting Standards Update No. 2015-03, unamortized debt issuance costs have been reclassified from other assets to long-term debt on a retrospective basis. This reclassification had no impact on historical income from continuing operations or members’ equity.
Borrowing Base Utilization Grid	Borrowing Base Utilization Grid Borrowing Base Utilization Percentage <25% > 25% <50% > 50% <75% > 75% <90% > 90% Eurodollar Loans Margin 1.50 % 1.75 % 2.00 % 2.25 % 2.50 % ABR Loans Margin 0.50 % 0.75 % 1.00 % 1.25 % 1.50 % Commitment Fee Rate 0.50 % 0.50 % 0.375 % 0.375 % 0.375 % Letter of Credit Fee 0.50 % 0.75 % 1.00 % 1.25 % 1.50 %

Price and Interest Rate Risk 21

Price and Interest Rate Risk Management Activities (Tables)	3 Months Ended
	Mar. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Commodity Derivative Contracts Covering Anticipated Future Production	At March 31, 2016 , the Company had open commodity derivative contracts covering our anticipated future production as follows: Fixed-Price Swaps (NYMEX) Gas Oil NGLs Contract Period MMBtu Weighted Average Fixed Price Bbls Weighted Average WTI Price Bbls Weighted Average April 1, 2016 – December 31, 2016 54,635,416 $ 4.36 1,406,822 $ 84.01 680,950 $ 30.31 January 1, 2017 – December 31, 2017 40,912,760 $ 3.95 749,698 $ 85.70 — $ — Fixed-Price Swaps (Light Louisiana Sweet) Oil Contract Period Bbls Weighted Average Fixed Price January 1, 2017 – December 31, 2017 168,000 $ 91.25 Call Options Sold Gas Oil Contract Period MMBtu Weighted Average Fixed Price Bbls Weighted Average Fixed Price April 1, 2016 – December 31, 2016 6,875,000 $ 4.25 467,500 $ 50.00 January 1, 2017 – December 31, 2017 9,125,000 $ 3.00 365,000 $ 95.00 Swaptions Gas Contract Period MMBtu Weighted Average Fixed Price January 1, 2017 – December 31, 2017 2,062,500 $ 2.74 January 1, 2018 – December 31, 2018 675,000 $ 2.74 Basis Swaps Gas Contract Period MMBtu Weighted Avg. Basis Differential ($/MMBtu) Pricing Index April 1, 2016 – December 31, 2016 28,875,000 $ (0.20 ) Northwest Rocky Mountain Pipeline and NYMEX Henry Hub Basis Differential January 1, 2017 – December 31, 2017 10,950,000 $ (0.22 ) Northwest Rocky Mountain Pipeline and NYMEX Henry Hub Basis Differential April 1, 2016 – December 31, 2016 726,084 $ (0.08 ) Houston Ship Channel and NYMEX Henry Hub Basis Differential April 1, 2016 – December 31, 2016 212,602 $ (0.10 ) TexOk and NYMEX Henry Hub Basis Differential April 1, 2016 – December 31, 2016 1,194,818 $ (0.13 ) WAHA and NYMEX Henry Hub Basis Differential Oil Contract Period Bbls Weighted Avg. Basis Differential ($/Bbl) Pricing Index April 1, 2016 – December 31, 2016 727,350 $ (1.01 ) WTI Midland and WTI Cushing Basis Differential April 1, 2016 – December 31, 2016 165,000 $ (0.43 ) West Texas Sour and WTI Cushing Basis Differential April 1, 2016 – December 31, 2016 550,000 $ (14.25 ) WTI and West Canadian Select Basis Differential Three-Way Collars Gas Contract Period MMBtu Floor Ceiling Put Sold April 1, 2016 – December 31, 2016 9,625,000 $ 3.95 $ 4.25 $ 3.00 January 1, 2017 – December 31, 2017 16,425,000 $ 3.92 $ 4.23 $ 3.37 Oil Contract Period Bbls Floor Ceiling Put Sold April 1, 2016 – December 31, 2016 797,500 $ 90.00 $ 96.18 $ 73.62 Put Options Sold Gas Oil Contract Period MMBtu Put Sold ($/MMBtu) Bbls Put Sold ($/Bbl) April 1, 2016 – December 31, 2016 1,375,000 $ 3.00 110,000 $ 75.00 January 1, 2017 – December 31, 2017 1,825,000 $ 3.50 73,000 $ 75.00 Range Bonus Accumulators Oil Contract Period Bbls Bonus Range Ceiling Range Floor April 1, 2016 – December 31, 2016 137,500 $ 4.00 $ 100.00 $ 75.00 Collars Oil Contract Period Bbls Floor Price ($/Bbl) Ceiling Price ($/Bbl) April 1, 2016 – December 31, 2016 366,000 $ 38.00 $ 47.25 Puts Oil Contract Period Bbls Put Price ($/Bbl) April 1, 2016 – December 31, 2016 275,000 $ 60.00
Interest Rate Derivative Contracts	Interest Rate Swaps At March 31, 2016 , we had open interest rate derivative contracts as follows (in thousands): Period Notional Amount Fixed LIBOR Rates April 1, 2016 to December 10, 2016 $ 20,000 2.17 % April 1, 2016 to October 31, 2016 $ 40,000 1.65 % April 1, 2016 to August 5, 2018 $ 30,000 2.25 % April 1, 2016 to August 6, 2016 $ 25,000 1.80 % April 1, 2016 to October 31, 2016 $ 20,000 1.78 % April 1, 2016 to September 23, 2016 $ 75,000 1.15 % April 1, 2016 to September 7, 2016 $ 25,000 1.25 % April 1, 2016 to December 31, 2019 $ 175,000 2.32 % April 1, 2016 to February 16, 2017 $ 75,000 1.73 % April 1, 2016 to June 16, 2017 $ 70,000 1.43 % April 1, 2016 to February 16, 2017 $ 75,000 1.73 % Total $ 630,000
Fair Value of Derivatives Outstanding	Our commodity derivatives and interest rate swap derivatives are presented on a net basis in “derivative assets” and “derivative liabilities” on the Consolidated Balance Sheets as governed by the International Swaps and Derivatives Association Master Agreement with each of the counterparties. The following table summarizes the gross fair values of our derivative instruments, presenting the impact of offsetting the derivative assets and liabilities on our Consolidated Balance Sheets for the periods indicated (in thousands): March 31, 2016 Offsetting Derivative Assets: Gross Amounts of Recognized Assets Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets Commodity price derivative contracts $ 305,292 $ (20,901 ) $ 284,391 Interest rate derivative contracts — (12,573 ) (12,573 ) Total derivative instruments $ 305,292 $ (33,474 ) $ 271,818 Offsetting Derivative Liabilities: Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets Commodity price derivative contracts $ (20,900 ) $ 20,900 $ — Interest rate derivative contracts (12,742 ) 12,574 (168 ) Total derivative instruments $ (33,642 ) $ 33,474 $ (168 ) December 31, 2015 Offsetting Derivative Assets: Gross Amounts of Recognized Assets Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets Commodity price derivative contracts $ 349,281 $ (21,834 ) $ 327,447 Interest rate derivative contracts — (10,400 ) (10,400 ) Total derivative instruments $ 349,281 $ (32,234 ) $ 317,047 Offsetting Derivative Liabilities: Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Consolidated Balance Sheets Net Amounts Presented in the Consolidated Balance Sheets Commodity price derivative contracts $ (21,934 ) $ 21,834 $ (100 ) Interest rate derivative contracts (10,656 ) 10,400 (256 ) Total derivative instruments $ (32,590 ) $ 32,234 $ (356 )
Reported Gains and Losses on Derivative Instruments	Changes in fair value of our commodity and interest rate derivatives for the three months ended March 31, 2016 and the year ended December 31, 2015 are as follows: Three Months Ended March 31, 2016 Year Ended December 31, 2015 (in thousands) Derivative asset at beginning of period, net $ 316,691 $ 220,734 Purchases Fair value of derivatives acquired — 195,273 Premiums and fees paid or deferred for derivative contracts (2,097 ) 7,126 Net gains on commodity and interest rate derivative contracts 27,068 169,569 Settlements Cash settlements received on matured commodity derivative contracts (72,617 ) (211,723 ) Cash settlements paid on matured interest rate derivative contracts 2,605 5,227 Termination of derivative contracts — (69,515 ) Derivative asset at end of period, net $ 271,650 $ 316,691

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Financial Assets and Financial Liabilities Measured at Fair Value on a Recurring Basis	Financial assets and financial liabilities measured at fair value on a recurring basis are summarized below (in thousands): March 31, 2016 Fair Value Measurements Using Assets/Liabilities Level 1 Level 2 Level 3 at Fair value Assets: Commodity price derivative contracts $ — $ 288,800 $ (4,409 ) $ 284,391 Interest rate derivative contracts — (12,573 ) — (12,573 ) Total derivative instruments $ — $ 276,227 $ (4,409 ) $ 271,818 Liabilities: Interest rate derivative contracts $ — $ (168 ) $ — $ (168 ) Total derivative instruments $ — $ (168 ) $ — $ (168 ) December 31, 2015 Fair Value Measurements Using Assets/Liabilities Level 1 Level 2 Level 3 at Fair value Assets: Commodity price derivative contracts $ — $ 333,380 $ (5,933 ) $ 327,447 Interest rate derivative contracts — (10,400 ) — (10,400 ) Total derivative instruments $ — $ 322,980 $ (5,933 ) $ 317,047 Liabilities: Commodity price derivative contracts $ — $ (99 ) $ — $ (99 ) Interest rate derivative contracts — (257 ) — (257 ) Total derivative instruments $ — $ (356 ) $ — $ (356 )
Reconciliation of changes in the fair value of assets and liabilities classified as Level 3	The following table sets forth a reconciliation of changes in the fair value of financial assets and liabilities classified as Level 3 (unobservable inputs) in the fair value hierarchy: Three Months Ended March 31, 2016 2015 (in thousands) Unobservable inputs, beginning of period $ (5,933 ) $ (6,470 ) Total gains 3,412 1,287 Settlements (1,888 ) (1,152 ) Unobservable inputs, end of period $ (4,409 ) $ (6,335 ) Change in fair value included in earnings related to derivatives still held as of March 31, $ (84 ) $ (804 )

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	3 Months Ended
	Mar. 31, 2016
Asset Retirement Obligation [Abstract]
Changes in Asset Retirement Obligations	The asset retirement obligations as of March 31, 2016 and December 31, 2015 reported on our Consolidated Balance Sheets and the changes in the asset retirement obligations for the three months ended March 31, 2016 and the year ended December 31, 2015 were as follows: March 31, 2016 December 31, 2015 (in thousands) Asset retirement obligations, beginning of period $ 271,456 $ 149,062 Liabilities added during the current period 143 2,699 Liabilities added from the LRE and Eagle Rock Mergers — 88,228 Accretion expense 3,113 10,238 Retirements (32 ) (838 ) Liabilities related to assets divested (2,102 ) (262 ) Change in estimate (2,007 ) 22,329 Asset retirement obligation, end of period 270,571 271,456 Less: current obligations (9,024 ) (9,024 ) Long-term asset retirement obligation, end of period $ 261,547 $ 262,432

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Future minimum transportation demand charges	The values in the table below represent gross future minimum transportation demand charges we are obligated to pay as of March 31, 2016 . However, our financial statements will reflect our proportionate share of the charges based on our working interest and net revenue interest, which will vary from property to property. March 31, 2016 (in thousands) April 1, 2016 - December 31, 2016 $ 10,964 2017 12,512 2018 11,696 2019 9,661 2020 410 Total $ 45,243

Members_ Deficit and Net Loss25

Members’ Deficit and Net Loss per Common and Class B Unit (Tables)	3 Months Ended
	Mar. 31, 2016
Equity [Abstract]
Cumulative Preferred Units	The following table summarizes the Company’s Cumulative Preferred Units outstanding at March 31, 2016 and December 31, 2015 : March 31, 2016 December 31, 2015 Earliest Redemption Date Liquidation Preference Per Unit Distribution Rate Units Outstanding Carrying Value Units Outstanding Carrying Value Series A June 15, 2023 $25.00 7.875% 2,581,873 $ 62,200 2,581,873 $ 62,200 Series B April 15, 2024 $25.00 7.625% 7,000,000 $ 169,265 7,000,000 $ 169,265 Series C October 15, 2024 $25.00 7.75% 4,300,000 $ 103,979 4,300,000 $ 103,979 Total Cumulative Preferred Units 13,881,873 $ 335,444 13,881,873 $ 335,444
Schedule of Common and Class B Units Outstanding Roll Forward	The following is a summary of the changes in our common units issued during the three months ended March 31, 2016 and the year ended December 31, 2015 (in thousands): March 31, 2016 December 31, 2015 Beginning of period 130,477 83,452 Issuance of Common units as consideration for the Eagle Rock Merger — 27,886 Issuance of Common units as consideration for the LRE Merger — 15,448 Issuance of Common units for cash — 2,430 Repurchase of units under the Common unit buyback program — (157 ) Unit-based compensation 489 1,418 End of period 130,966 130,477
Distributions Declared	The following table shows the distribution amount per unit, declared date, record date and payment date of the cash distributions we paid on each of our common and Class B units attributable to each period presented. Future distributions are at the discretion of our board of directors and will depend on business conditions, earnings, our cash requirements and other relevant factors. As discussed above, our board of directors elected to suspend cash distributions to the holders of our common and Class B units and Cumulative Preferred Units effective with the February 2016 distribution. Cash Distributions Distribution Per Unit Declared Date Record Date Payment Date 2016 First Quarter January $ 0.0300 February 18, 2016 March 1, 2016 March 15, 2016 2015 Fourth Quarter December $ 0.0300 January 20, 2016 February 1, 2016 February 12, 2016 November $ 0.0300 December 18, 2015 January 4, 2016 January 14, 2016 October $ 0.1175 November 20, 2015 December 1, 2015 December 15, 2015 Third Quarter September $ 0.1175 October 19, 2015 November 2, 2015 November 13, 2015 August $ 0.1175 September 21, 2015 October 1, 2015 October 15, 2015 July $ 0.1175 August 20, 2015 September 1, 2015 September 14, 2015 Second Quarter June $ 0.1175 July 16, 2015 August 3, 2015 August 14, 2015 May $ 0.1175 June 18, 2015 July 1, 2015 July 15, 2015 April $ 0.1175 May 19, 2015 June 1, 2015 June 12, 2015 First Quarter March $ 0.1175 April 15, 2015 May 1, 2015 May 15, 2015 February $ 0.1175 March 18, 2015 April 1, 2015 April 14, 2015 January $ 0.1175 February 17, 2015 March 2, 2015 March 17, 2015 2014 Fourth Quarter December $ 0.2100 January 22, 2015 February 2, 2015 February 13, 2015

Unit-Based Compensation (Tables

Unit-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Compensation, Restricted Stock Units Award Activity	A summary of the status of the non-vested restricted units as of March 31, 2016 is presented below: Number of Non-vested Restricted Units Weighted Average Grant Date Fair Value Non-vested restricted units at December 31, 2015 976,348 $ 18.29 Granted 7,500 $ 3.11 Forfeited (8,500 ) $ 15.64 Vested (209,708 ) $ 19.37 Non-vested restricted units at March 31, 2016 765,640 $ 17.88
Schedule of Nonvested Phantom Units Activity	A summary of the status of the non-vested phantom units under the VNR LTIP as of March 31, 2016 is presented below: Number of Non-vested Phantom Units Weighted Average Grant Date Fair Value Non-vested restricted units at December 31, 2015 203,221 $ 20.99 Granted 2,380,871 $ 2.98 Forfeited (262 ) $ 19.62 Non-vested phantom units at March 31, 2016 2,583,830 $ 4.39

Description of the Business (De

Description of the Business (Details)	3 Months Ended
	Mar. 31, 2016operating_areas
Accounting Policies [Abstract]
Number of operating areas	10

Summary of Significant Accoun28

Summary of Significant Accounting Policies (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016USD ($)$ / bbl$ / MMBTU	Mar. 31, 2015USD ($)$ / bbl$ / MMBTU
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Discount rate used in determining limitation of capitalized costs (in hundredths)	10.00%
Impairment of oil and natural gas properties | $	$ 207,764	$ 132,610
Average price of natural gas used in the impairment calculation | $ / MMBTU	2.41	3.91
Average price of crude oil used in the impairment calculation | $ / bbl	46.16	82.62

Acquisitions and Divestitures -

Acquisitions and Divestitures - Acquisitions (LRE Merger) (Details) $ / shares in Units, $ in Thousands	Oct. 05, 2015USD ($)$ / sharesshares	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Less: fair value of assets acquired
Goodwill		$ 506,046	$ 506,046
LRE Merger [Member]
Business Acquisition [Line Items]
Business Combination, Equity Interest Issued or Issuable, Exchange Ratio	0.550
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares | shares	15,400,000
Business Acquisition, Share Price | $ / shares	$ 7.98
Business Combination, Consideration Transferred [Abstract]
Market value of Vanguard’s common units issued to LRE unitholders	$ 123,276
Long-term debt assumed	290,000
Business Combination, Consideration Transferred	413,276
Add: fair value of liabilities assumed
Accounts payable and accrued liabilities	5,606
Other current liabilities	9,018
Asset retirement obligations	39,595
Amount attributable to liabilities assumed	54,219
Less: fair value of assets acquired
Cash	11,532
Trade accounts receivable	6,822
Other current assets	4,172
Oil and natural gas properties	209,463
Derivative assets	78,725
Other assets	267
Amount attributable assets acquired	310,981
Goodwill	$ 156,514
General Partner [Member] | LRE Merger [Member]
Business Acquisition [Line Items]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares | shares	12,320

Acquisitions and Divestitures30

Acquisitions and Divestitures - Acquisitions (Eagle Rock Merger) (Details) - EROC Merger [Member] $ / shares in Units, $ in Thousands, shares in Millions	Oct. 08, 2015USD ($)$ / sharesshares
Business Acquisition [Line Items]
Business Combination, Equity Interest Issued or Issuable, Exchange Ratio	0.185
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares | shares	27.7
Business Acquisition, Share Price | $ / shares	$ 9.31
Debt extinguished subsequent to the merger	$ 122,300
Business Combination, Consideration Transferred [Abstract]
Market value of Vanguard’s common units issued to Eagle Rock unitholders	258,282
Long-term debt assumed	156,550
Replacement unit-based payment awards attributable to pre-combination services	346
Business Combination, Consideration Transferred	415,178
Add: fair value of liabilities assumed
Accounts payable and accrued liabilities	53,255
Other current liabilities	2,206
Derivative liabilities	2,201
Asset retirement obligations	48,633
Deferred tax liability	39,327
Other long-term liabilities	1,244
Amount attributable to liabilities assumed	146,866
Less: fair value of assets acquired
Cash	6,971
Trade accounts receivable	17,543
Other current assets	15,664
Oil and natural gas properties	462,715
Derivative assets	90,234
Other assets	9,734
Amount attributable assets acquired	602,861
Bargain Purchase Gain	$ (40,817)

Acquisitions and Divestitures31

Acquisitions and Divestitures (Details) - USD ($)	Jul. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
Business Acquisition [Line Items]
Ownership interest conveyed		51.00%
Proceeds from Sale of Oil and Gas Property and Equipment		$ 21,114,000	$ 0
Series of Individually Immaterial Business Acquisitions [Member]
Business Acquisition [Line Items]
Fair value of consideration transferred	$ 11,400,000
Proceeds from Sale of Oil and Gas Property and Equipment		21.1
SCOOP/STACK Divestiture [Member]
Business Acquisition [Line Items]
Business acquisitions, Agreed purchase price		280,000,000
Potato Hills Gas Gathering System [Member]
Business Acquisition [Line Items]
Fair value of consideration transferred		$ 7,700,000

Acquisitions and Divestitures32

Acquisitions and Divestitures - Pro Forma (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2015USD ($)$ / shares
Business Acquisition, Pro Forma Information [Abstract]
Proforma revenues	$ 246,252
Proforma Net income	$ (197,992)
Net loss per unit
Business Acquisition, Pro Forma Earnings Per Share, Basic and Diluted | $ / shares	$ (1.55)

Acquisitions and Divestitures33

Acquisitions and Divestitures - Acquiree Earnings (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016USD ($)
EROC Merger [Member]
Business Acquisition [Line Items]
Revenues	$ 18,972
Excess of revenues over direct operating expenses	10,541
LRE Merger [Member]
Business Acquisition [Line Items]
Revenues	4,540
Excess of revenues over direct operating expenses	$ 1,492

Long-Term Debt (Details)

Long-Term Debt (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2016		Mar. 31, 2015	Jan. 01, 2017	Feb. 10, 2016	Jan. 01, 2016	Dec. 31, 2015
Senior Secured Reserve-Based Credit Facility [Abstract]
Debt amount outstanding		$ 2,202,144						$ 2,313,788
Current Ratio		100.00%
Debt to EBITDA ratio							525.00%
Senior Notes [Abstract]
Unamortized discount on Senior Notes		$ 16,038						17,651
Unamortized Debt Issuance Expense		(12,563)	[1]					(13,705)
Long-term Debt, Current Maturities		4,548						4,501
Long-term Debt, Excluding Current Maturities		$ 2,168,995						2,277,931
Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions		100.00%
Required repurchase of aggregate amount of debt		$ 50,000
Gains (Losses) on Extinguishment of Debt		89,714		$ 0
Carrying Value of Senior Notes exchanged, Net						$ 165,300
Extinguishment of Debt, Amount		168,200
Senior Secured Reserve-Based Credit Facility
Senior Secured Reserve-Based Credit Facility [Abstract]
Line of Credit Facility, Maximum Borrowing Capacity		3,500,000
Line of Credit Facility, Current Borrowing Capacity		1,780,000
Debt amount outstanding		1,670,000						1,688,000
Remaining borrowing capacity		$ 106,600
Senior Notes [Abstract]
Maturity date		Apr. 16, 2018
Authorized distribution to unitholders		$ 57,000
Senior Notes due 2019 [Member]
Senior Secured Reserve-Based Credit Facility [Abstract]
Debt amount outstanding		$ 51,120						51,120
Senior Notes [Abstract]
Debt Instrument, Interest Rate, Effective Percentage		21.45%
Redemption price of aggregate principal amount of senior notes on or after April 1, 2016 (in hundredths)		102.094%
Stated interest rate (in hundredths)	[2]	8.375%
Maturity date		Jun. 1, 2019
Redemption price of aggregate principal amount of senior notes on April 1, 2018 and thereafter (in hundredths)		100.00%
Senior Notes due 2020 [Member]
Senior Secured Reserve-Based Credit Facility [Abstract]
Debt amount outstanding		$ 381,830						550,000
Senior Notes [Abstract]
Debt Instrument, Interest Rate, Effective Percentage		8.00%
Redemption price of aggregate principal amount of senior notes on or after April 1, 2016 (in hundredths)		103.9375%
Stated interest rate (in hundredths)	[3]	7.875%
Maturity date		Apr. 1, 2020
Redemption price of aggregate principal amount of senior notes on April 1, 2018 and thereafter (in hundredths)		100.00%
Redemption price of aggregate principal amount of senior notes at any time prior to April 1, 2016 (in hundredths)		100.00%
Required repurchase price of aggregate principal amount of senior notes, lower range (in hundredths)		100.00%
Required repurchase price of aggregate principal amount of senior notes, upper range (in hundredths)		101.00%
Subordinated Debt due 2023
Senior Secured Reserve-Based Credit Facility [Abstract]
Debt amount outstanding		$ 75,634						0
Senior Notes [Abstract]
Stated interest rate (in hundredths)		7.00%
Maturity date		Feb. 15, 2023
Lease Financing Obligations
Senior Secured Reserve-Based Credit Facility [Abstract]
Debt amount outstanding		$ 23,560						$ 24,668
Senior Notes [Abstract]
Stated interest rate (in hundredths)		4.16%
Maturity date	[4]	Aug. 10, 2020
Aggregate Cost, Early Buyout Option to Purchase equipment		$ 16,000
Standby Letters of Credit | Senior Secured Reserve-Based Credit Facility
Senior Secured Reserve-Based Credit Facility [Abstract]
Line of Credit Facility, Current Borrowing Capacity		$ 4,500
Scenario, Forecast [Member]
Senior Secured Reserve-Based Credit Facility [Abstract]
Debt to EBITDA ratio					450.00%
[1]	In order to comply with Accounting Standards Update No. 2015-03, unamortized debt issuance costs have been reclassified from other assets to long-term debt on a retrospective basis. This reclassification had no impact on historical income from continuing operations or members’ equity.
[2]	Effective interest rate was 21.45%.
[3]	Effective interest rate was 8.00%.
[4]	The Lease Financing Obligations expire on August 10, 2020, except for certain obligations which expire on July 10, 2021.

Long-Term Debt - Financing Arra

Long-Term Debt - Financing Arrangements (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2016		Dec. 31, 2015
Debt Instrument [Line Items]
Debt amount outstanding		$ 2,202,144		$ 2,313,788
Unamortized discount on Senior Notes		(16,038)		(17,651)
Unamortized deferred financing costs		(12,563)	[1]	(13,705)
Current portion of Lease Financing Obligation		(4,548)		(4,501)
Total long-term debt		$ 2,168,995		$ 2,277,931
Senior Secured Reserve-Based Credit Facility
Debt Instrument [Line Items]
Interest rate description	[2]	Variable (1)
Maturity date		Apr. 16, 2018
Variable interest rate		2.94%		2.90%
Debt amount outstanding		$ 1,670,000		$ 1,688,000
Senior Notes due 2019 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)	[3]	8.375%
Maturity date		Jun. 1, 2019
Debt Instrument, Interest Rate, Effective Percentage		21.45%
Debt amount outstanding		$ 51,120		51,120
Senior Notes due 2020 [Member]
Debt Instrument [Line Items]
Stated interest rate (in hundredths)	[4]	7.875%
Maturity date		Apr. 1, 2020
Debt Instrument, Interest Rate, Effective Percentage		8.00%
Debt amount outstanding		$ 381,830		550,000
Subordinated Debt due 2023
Debt Instrument [Line Items]
Stated interest rate (in hundredths)		7.00%
Maturity date		Feb. 15, 2023
Debt amount outstanding		$ 75,634		0
Lease Financing Obligations
Debt Instrument [Line Items]
Stated interest rate (in hundredths)		4.16%
Maturity date	[5]	Aug. 10, 2020
Debt amount outstanding		$ 23,560		$ 24,668
[1]	In order to comply with Accounting Standards Update No. 2015-03, unamortized debt issuance costs have been reclassified from other assets to long-term debt on a retrospective basis. This reclassification had no impact on historical income from continuing operations or members’ equity.
[2]	Variable interest rate was 2.94% and 2.90% at March 31, 2016 and December 31, 2015, respectively.
[3]	Effective interest rate was 21.45%.
[4]	Effective interest rate was 8.00%.
[5]	The Lease Financing Obligations expire on August 10, 2020, except for certain obligations which expire on July 10, 2021.

Long-Term Debt - Borrowing Base

Long-Term Debt - Borrowing Base Utilization Grid (Details)	3 Months Ended
	Mar. 31, 2016
Borrowing Base Utilization Less Than 25%
Debt Instrument [Line Items]
Commitment fee rate (in hundredths)	0.50%
Letter of credit fee (in hundredths)	0.50%
Borrowing Base Utilization Less Than 25% | Eurodollar Loans Margin
Debt Instrument [Line Items]
Loans margin (in hundredths)	1.50%
Borrowing Base Utilization Less Than 25% | ABR Loans Margin
Debt Instrument [Line Items]
Loans margin (in hundredths)	0.50%
Borrowing Base Utilization Greater Than Or Equal To 25% But Less Than 50%
Debt Instrument [Line Items]
Commitment fee rate (in hundredths)	0.50%
Letter of credit fee (in hundredths)	0.75%
Borrowing Base Utilization Greater Than Or Equal To 25% But Less Than 50% | Eurodollar Loans Margin
Debt Instrument [Line Items]
Loans margin (in hundredths)	1.75%
Borrowing Base Utilization Greater Than Or Equal To 25% But Less Than 50% | ABR Loans Margin
Debt Instrument [Line Items]
Loans margin (in hundredths)	0.75%
Borrowing Base Utilization Greater Than Or Equal To 50% But Less Than 75%
Debt Instrument [Line Items]
Commitment fee rate (in hundredths)	0.375%
Letter of credit fee (in hundredths)	1.00%
Borrowing Base Utilization Greater Than Or Equal To 50% But Less Than 75% | Eurodollar Loans Margin
Debt Instrument [Line Items]
Loans margin (in hundredths)	2.00%
Borrowing Base Utilization Greater Than Or Equal To 50% But Less Than 75% | ABR Loans Margin
Debt Instrument [Line Items]
Loans margin (in hundredths)	1.00%
Borrowing Base Utilization Greater Than Or Equal To 75% But Less Than 90%
Debt Instrument [Line Items]
Commitment fee rate (in hundredths)	0.375%
Letter of credit fee (in hundredths)	1.25%
Borrowing Base Utilization Greater Than Or Equal To 75% But Less Than 90% | Eurodollar Loans Margin
Debt Instrument [Line Items]
Loans margin (in hundredths)	2.25%
Borrowing Base Utilization Greater Than Or Equal To 75% But Less Than 90% | ABR Loans Margin
Debt Instrument [Line Items]
Loans margin (in hundredths)	1.25%
Borrowing Base Utilization Equal To Or Greater Than 90%
Debt Instrument [Line Items]
Commitment fee rate (in hundredths)	0.375%
Letter of credit fee (in hundredths)	1.50%
Borrowing Base Utilization Equal To Or Greater Than 90% | Eurodollar Loans Margin
Debt Instrument [Line Items]
Loans margin (in hundredths)	2.50%
Borrowing Base Utilization Equal To Or Greater Than 90% | ABR Loans Margin
Debt Instrument [Line Items]
Loans margin (in hundredths)	1.50%

Price and Interest Rate Risk 37

Price and Interest Rate Risk Management Activities (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016USD ($)MMBTU$ / bbl$ / MMBTUbbl
Fair value of derivatives [Abstract]
Maximum potential loss due to credit risk | $	$ 305,300
Fixed-Price Swaps | Gas | Contract Period April 1, 2016 to December 31, 2016 [Member]
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Gas Production Being Hedged | MMBTU	54,635,416
Weighted average fixed price (in dollars per unit) | $ / MMBTU	4.36
Fixed-Price Swaps | Gas | Contract period January 1, 2017 to December 31, 2017
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Gas Production Being Hedged | MMBTU	40,912,760
Weighted average fixed price (in dollars per unit) | $ / MMBTU	3.95
Fixed-Price Swaps | Oil | Contract Period April 1, 2016 to December 31, 2016 [Member]
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Oil and liquids Production Being Hedged | bbl	1,406,822
Weighted average fixed price (in dollars per unit)	84.01
Fixed-Price Swaps | Oil | Contract period January 1, 2017 to December 31, 2017
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Oil and liquids Production Being Hedged | bbl	749,698
Weighted average fixed price (in dollars per unit)	85.70
Fixed-Price Swaps | Oil | Contract period January 1, 2017 to December 31, 2017 | Light Louisiana Sweet [Member]
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Oil and liquids Production Being Hedged | bbl	168,000
Weighted average fixed price (in dollars per unit)	91.25
Fixed-Price Swaps | Natural Gas Liquids | Contract Period April 1, 2016 to December 31, 2016 [Member]
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Oil and liquids Production Being Hedged | bbl	680,950
Weighted average fixed price (in dollars per unit)	30.31
Fixed-Price Swaps | Natural Gas Liquids | Contract period January 1, 2017 to December 31, 2017
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Oil and liquids Production Being Hedged | bbl	0
Weighted average fixed price (in dollars per unit)	0
Call Option [Member] | Gas | Contract Period April 1, 2016 to December 31, 2016 [Member]
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Gas Production Being Hedged | MMBTU	6,875,000
Weighted average fixed price (in dollars per unit) | $ / MMBTU	4.25
Call Option [Member] | Gas | Contract period January 1, 2017 to December 31, 2017
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Gas Production Being Hedged | MMBTU	9,125,000
Weighted average fixed price (in dollars per unit) | $ / MMBTU	3
Call Option [Member] | Oil | Contract Period April 1, 2016 to December 31, 2016 [Member]
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Oil and liquids Production Being Hedged | bbl	467,500
Weighted average fixed price (in dollars per unit)	50
Call Option [Member] | Oil | Contract period January 1, 2017 to December 31, 2017
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Oil and liquids Production Being Hedged | bbl	365,000
Weighted average fixed price (in dollars per unit)	95
Swaption [Member] | Gas | Contract period January 1, 2017 to December 31, 2017
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Gas Production Being Hedged | MMBTU	2,062,500
Weighted average fixed price (in dollars per unit) | $ / MMBTU	2.74
Swaption [Member] | Gas | Contract period January 1, 2018 to December 31, 2018 [Member]
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Gas Production Being Hedged | MMBTU	675,000
Weighted average fixed price (in dollars per unit) | $ / MMBTU	2.74
Basis Swaps | Gas | Contract Period April 1, 2016 to December 31, 2016 [Member] | NW Rocky Mt-Henry Hub Index
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Gas Production Being Hedged | MMBTU	28,875,000
Weighted average basis differential (in dollars per unit) | $ / MMBTU	(0.20)
Basis Swaps | Gas | Contract Period April 1, 2016 to December 31, 2016 [Member] | Houston Ship Channel-Henry Hub Index [Member]
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Gas Production Being Hedged | MMBTU	726,084
Weighted average basis differential (in dollars per unit) | $ / MMBTU	(0.08)
Basis Swaps | Gas | Contract Period April 1, 2016 to December 31, 2016 [Member] | TexOk- Henry Hub Index [Member]
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Gas Production Being Hedged | MMBTU	212,602
Weighted average basis differential (in dollars per unit) | $ / MMBTU	(0.10)
Basis Swaps | Gas | Contract Period April 1, 2016 to December 31, 2016 [Member] | WAHA - Henry Hub Index [Member]
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Gas Production Being Hedged | MMBTU	1,194,818
Weighted average basis differential (in dollars per unit) | $ / MMBTU	(0.13)
Basis Swaps | Gas | Contract period January 1, 2017 to December 31, 2017 | NW Rocky Mt-Henry Hub Index
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Gas Production Being Hedged | MMBTU	10,950,000
Weighted average basis differential (in dollars per unit) | $ / MMBTU	(0.22)
Basis Swaps | Oil | Contract Period April 1, 2016 to December 31, 2016 [Member] | Midland-Cushing Index
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Oil and liquids Production Being Hedged | bbl	727,350
Weighted average basis differential (in dollars per unit)	(1.01)
Basis Swaps | Oil | Contract Period April 1, 2016 to December 31, 2016 [Member] | WTS-Cushing Index
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Oil and liquids Production Being Hedged | bbl	165,000
Weighted average basis differential (in dollars per unit)	(0.43)
Basis Swaps | Oil | Contract Period April 1, 2016 to December 31, 2016 [Member] | WTI-WCS Index
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Oil and liquids Production Being Hedged | bbl	550,000
Weighted average basis differential (in dollars per unit)	(14.25)
Three-Way Collars | Gas | Contract Period April 1, 2016 to December 31, 2016 [Member]
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Gas Production Being Hedged | MMBTU	9,625,000
Weighted average price (in dollars per unit) | $ / MMBTU	3
Floor (in dollars per unit) | $ / MMBTU	3.95
Ceiling (in dollars per unit) | $ / MMBTU	4.25
Three-Way Collars | Gas | Contract period January 1, 2017 to December 31, 2017
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Gas Production Being Hedged | MMBTU	16,425,000
Weighted average price (in dollars per unit) | $ / MMBTU	3.37
Floor (in dollars per unit) | $ / MMBTU	3.92
Ceiling (in dollars per unit) | $ / MMBTU	4.23
Three-Way Collars | Oil | Contract Period April 1, 2016 to December 31, 2016 [Member]
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Oil and liquids Production Being Hedged | bbl	797,500
Weighted average price (in dollars per unit)	73.62
Floor (in dollars per unit)	90
Ceiling (in dollars per unit)	96.18
Put Options Sold | Gas | Contract Period April 1, 2016 to December 31, 2016 [Member]
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Gas Production Being Hedged | MMBTU	1,375,000
Weighted average price (in dollars per unit) | $ / MMBTU	3
Put Options Sold | Gas | Contract period January 1, 2017 to December 31, 2017
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Gas Production Being Hedged | MMBTU	1,825,000
Weighted average price (in dollars per unit) | $ / MMBTU	3.50
Put Options Sold | Oil | Contract Period April 1, 2016 to December 31, 2016 [Member]
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Oil and liquids Production Being Hedged | bbl	110,000
Weighted average price (in dollars per unit)	75
Put Options Sold | Oil | Contract period January 1, 2017 to December 31, 2017
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Oil and liquids Production Being Hedged | bbl	73,000
Weighted average price (in dollars per unit)	75
Range Bonus Accumulators | Oil | Contract Period April 1, 2016 to December 31, 2016 [Member]
Commodity derivative contracts covering our anticipated future production [Abstract]
Floor (in dollars per unit)	75
Derivative, Nonmonetary Notional Amount, Volume | bbl	137,500
Ceiling (in dollars per unit)	100
Bonus (in dollars per unit)	4
Collars | Oil | Contract Period April 1, 2016 to December 31, 2016 [Member]
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Oil and liquids Production Being Hedged | bbl	366,000
Floor (in dollars per unit)	38
Ceiling (in dollars per unit)	47.25
Puts | Oil | Contract Period April 1, 2016 to December 31, 2016 [Member]
Commodity derivative contracts covering our anticipated future production [Abstract]
Portion of Future Oil and liquids Production Being Hedged | bbl	275,000
Derivative, Price Risk Option Strike Price	60
Interest Rate Swaps
Interest rate derivative contracts [Abstract]
Notional amount | $	$ 630,000
Interest Rate Swaps | Contract period April 1, 2015 to December 10, 2016 [Member]
Interest rate derivative contracts [Abstract]
Notional amount | $	$ 20,000
Fixed Libor Rates (in hundredths)	2.17%
Interest Rate Swaps | Contract Period April 1, 2016 to October 31, 2016 swap B [Member]
Interest rate derivative contracts [Abstract]
Notional amount | $	$ 40,000
Fixed Libor Rates (in hundredths)	1.65%
Interest Rate Swaps | Contract Period April 1, 2016 to August 5, 2018 [Member]
Interest rate derivative contracts [Abstract]
Notional amount | $	$ 30,000	[1]
Fixed Libor Rates (in hundredths)	2.25%	[1]
Interest Rate Swaps | Contract Period April 1, 2016 to August 6, 2016 [Member]
Interest rate derivative contracts [Abstract]
Notional amount | $	$ 25,000
Fixed Libor Rates (in hundredths)	1.80%
Interest Rate Swaps | Contract Period April 1, 2016 to October 31, 2016 [Member]
Interest rate derivative contracts [Abstract]
Notional amount | $	$ 20,000
Fixed Libor Rates (in hundredths)	1.78%
Interest Rate Swaps | Contract Period April 1, 2016 to September 23, 2016 [Member]
Interest rate derivative contracts [Abstract]
Notional amount | $	$ 75,000
Fixed Libor Rates (in hundredths)	1.149%
Interest Rate Swaps | Contract Period April 1, 2016 to September 7, 2016 [Member]
Interest rate derivative contracts [Abstract]
Notional amount | $	$ 25,000
Fixed Libor Rates (in hundredths)	1.25%
Interest Rate Swaps | Contract Period April 1, 2016 to December 31, 2019 [Member]
Interest rate derivative contracts [Abstract]
Notional amount | $	$ 175,000
Fixed Libor Rates (in hundredths)	2.3195%
Interest Rate Swaps | Contract Period April 1, 2016 to February 16, 2017 swap A [Member]
Interest rate derivative contracts [Abstract]
Notional amount | $	$ 75,000
Fixed Libor Rates (in hundredths)	1.7275%
Interest Rate Swaps | Contract Period April 1, 2016 to June 16, 2017 [Member]
Interest rate derivative contracts [Abstract]
Notional amount | $	$ 70,000
Fixed Libor Rates (in hundredths)	1.4275%
Interest Rate Swaps | Contract Period April 1, 2016 to February 16, 2017 [Member]
Interest rate derivative contracts [Abstract]
Notional amount | $	$ 75,000
Fixed Libor Rates (in hundredths)	1.725%
[1]	{F|ahBzfndlYmZpbGluZ3MtaHJkcmoLEgZYTUxEb2MiXlhCUkxEb2NHZW5JbmZvOmFhNDliZjA2N2U4MjQwYTA4MzI0OWZlNDQyZDg4NTdjfFRleHRTZWxlY3Rpb246RDVCMkVGNTNENTZERTg3OEFENjE2Mjk1NzNFMjY4NjUM}

Price and Interest Rate Risk 38

Price and Interest Rate Risk Management Activities - Balance Sheet Presentation (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Offsetting Derivative Assets:
Gross amounts of recognized assets	$ 305,292	$ 349,281
Gross amounts offset in the consolidated balance sheets	(33,474)	(32,234)
Net Amounts Presented in the Consolidated Balance Sheets	271,818	317,047
Offsetting Derivative Liabilities:
Gross amounts of recognized liabilities	(33,642)	(32,590)
Gross amounts offset in the consolidated balance sheets	33,474	32,234
Net Amounts Presented in the Consolidated Balance Sheets	(168)	(356)
Commodity Contract
Offsetting Derivative Assets:
Gross amounts of recognized assets	305,292	349,281
Gross amounts offset in the consolidated balance sheets	(20,901)	(21,834)
Net Amounts Presented in the Consolidated Balance Sheets	284,391	327,447
Offsetting Derivative Liabilities:
Gross amounts of recognized liabilities	(20,900)	(21,934)
Gross amounts offset in the consolidated balance sheets	20,900	21,834
Net Amounts Presented in the Consolidated Balance Sheets	0	(100)
Interest Rate Contract
Offsetting Derivative Assets:
Gross amounts of recognized assets	0	0
Gross amounts offset in the consolidated balance sheets	(12,573)	(10,400)
Net Amounts Presented in the Consolidated Balance Sheets	(12,573)	(10,400)
Offsetting Derivative Liabilities:
Gross amounts of recognized liabilities	(12,742)	(10,656)
Gross amounts offset in the consolidated balance sheets	12,574	10,400
Net Amounts Presented in the Consolidated Balance Sheets	$ (168)	$ (256)

Price and Interest Rate Risk 39

Price and Interest Rate Risk Management Activities - Change in Fair Value of Derivatives (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Fair Value, Net Derivative Asset (Liability), Reconciliation [Roll Forward]
Derivative asset at beginning of period, net	$ 316,691	$ 220,734	$ 220,734
Fair value of derivatives acquired			195,273
Premiums and fees paid or deferred for derivative contracts	(2,097)		7,126
Net gains on commodity and interest rate derivative contracts	27,068	57,830	169,569
Cash settlement received on matured commodity derivative contracts	(72,617)	(38,291)	(211,723)
Cash settlements paid on matured interest rate derivative contracts	2,605	$ 990	5,227
Termination of derivative contracts			(69,515)
Derivative asset at end of period, net	$ 271,650		$ 316,691

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Liabilities:
Asset retirement obligations incurred and recorded	$ 143	$ 2,699
Asset retirement obligations incurred and assumed from business combinations		90,900
Asset Retirement Obligation, Revision of Estimate	$ (2,007)	22,329
Average inflation rate (in hundredths)	1.97%
Fair Value Measured on a Recurring Basis
Assets:
Commodity price derivative contracts	$ 284,391	327,447
Interest Rate Derivative Assets, at Fair Value	(12,573)	(10,400)
Total derivative instruments	271,818	317,047
Liabilities:
Commodity price derivative contracts		(99)
Interest rate derivative contracts	(168)	(257)
Total derivative instruments	(168)	(356)
Fair Value Measured on a Recurring Basis | Fair Value Measurements Using Level 1
Assets:
Commodity price derivative contracts	0	0
Interest Rate Derivative Assets, at Fair Value	0	0
Total derivative instruments	0	0
Liabilities:
Commodity price derivative contracts		0
Interest rate derivative contracts	0	0
Total derivative instruments	0	0
Fair Value Measured on a Recurring Basis | Fair Value Measurements Using Level 2
Assets:
Commodity price derivative contracts	288,800	333,380
Interest Rate Derivative Assets, at Fair Value	(12,573)	(10,400)
Total derivative instruments	276,227	322,980
Liabilities:
Commodity price derivative contracts		(99)
Interest rate derivative contracts	(168)	(257)
Total derivative instruments	(168)	(356)
Fair Value Measured on a Recurring Basis | Fair Value Measurements Using Level 3
Assets:
Commodity price derivative contracts	(4,409)	(5,933)
Interest Rate Derivative Assets, at Fair Value	0	0
Total derivative instruments	(4,409)	(5,933)
Liabilities:
Commodity price derivative contracts		0
Interest rate derivative contracts	0	0
Total derivative instruments	$ 0	$ 0
Minimum
Liabilities:
Credit-adjusted risk-free interest rate (in hundredths)	4.60%
Maximum
Liabilities:
Credit-adjusted risk-free interest rate (in hundredths)	5.50%
Senior Notes due 2019 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Fair Value Disclosure	$ 7,300
Senior Notes due 2020 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Fair Value Disclosure	55,200
Subordinated Debt due 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Fair Value Disclosure	$ 84,100

Fair Value Measurements - Unobs

Fair Value Measurements - Unobservable Inputs Reconciliation (Details) - Fair Value Measurements Using Level 3 - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Unobservable inputs reconciliation
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	$ (5,933)	$ (6,470)
Total gains	3,412	1,287
Settlements	(1,888)	(1,152)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	(4,409)	(6,335)
Change in fair value included in earnings related to derivatives still held as of March 31,	$ (84)	$ (804)

Asset Retirement Obligations (D

Asset Retirement Obligations (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Changes in asset retirement obligations [Abstract]
Asset retirement obligations at beginning of period	$ 271,456	$ 149,062
Liabilities added during the current period	143	2,699
Asset retirement obligations assumed in a business combination		88,228
Accretion expense	3,113	10,238
Retirements	(32)	(838)
Disposition of properties	(2,102)	(262)
Change in estimate	(2,007)	22,329
Total asset retirement obligations at end of period	270,571	271,456
Less: current obligations	(9,024)	(9,024)
Long-term asset retirement obligation at end of period	$ 261,547	$ 262,432

Commitments and Contingencies -

Commitments and Contingencies - Transportation Demand Charges (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016USD ($)
Gross future minimum transportation demand
April 1, 2016 - December 31, 2016	$ 10,964
Due 2,017	12,512
Due 2,018	11,696
Due 2,019	9,661
Due 2,020	410
Total	$ 45,243
Minimum
Oil and Gas Delivery Commitments and Contracts
Oil and Gas Delivery Commitments and Contracts, Length of Contract	3 months
Maximum
Oil and Gas Delivery Commitments and Contracts
Oil and Gas Delivery Commitments and Contracts, Length of Contract	4 years

Members_ Deficit and Net Loss44

Members’ Deficit and Net Loss per Common and Class B Unit - Preferred Units Outstanding (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Liquidation Preference Per Share (usd per share)	$ 25
Units Outstanding (shares)	13,881,873	13,881,873
Carrying Value	$ 335,444	$ 335,444
Series A Preferred Units
Class of Stock [Line Items]
Liquidation Preference Per Share (usd per share)	$ 25
Distribution Rate	7.875%
Units Outstanding (shares)	2,581,873	2,581,873
Carrying Value	$ 62,200	$ 62,200
Preferred Stock, Amount of Preferred Dividends in Arrears	$ 400
Series B Preferred Unit
Class of Stock [Line Items]
Liquidation Preference Per Share (usd per share)	$ 25
Distribution Rate	7.625%
Units Outstanding (shares)	7,000,000	7,000,000
Carrying Value	$ 169,265	$ 169,265
Preferred Stock, Amount of Preferred Dividends in Arrears	$ 1,100
Series C Preferred Units
Class of Stock [Line Items]
Liquidation Preference Per Share (usd per share)	$ 25
Distribution Rate	7.75%
Units Outstanding (shares)	4,300,000	4,300,000
Carrying Value	$ 103,979	$ 103,979
Preferred Stock, Amount of Preferred Dividends in Arrears	$ 700

Members_ Deficit and Net Loss45

Members’ Deficit and Net Loss per Common and Class B Unit - Common and Class B Units Rollforward (Details) - shares shares in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Common Units
Increase (Decrease) in Members' Equity [Roll Forward]
Beginning of period (shares)	130,477	83,452
Issuance of Common units for cash (shares)	0	2,430
Repurchase of units under the Common unit buyback program (shares)	0	(157)
Unit-based compensation (shares)	489	1,418
End of period (shares)	130,966	130,477
EROC Merger [Member]
Increase (Decrease) in Members' Equity [Roll Forward]
Partners' Capital Account, Units, Acquisitions	0	27,886
LRE Merger [Member]
Increase (Decrease) in Members' Equity [Roll Forward]
Partners' Capital Account, Units, Acquisitions	0	15,448

Members_ Deficit and Net Loss46

Members’ Deficit and Net Loss per Common and Class B Unit - Net Income per Unit (Details) - shares	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Equity [Abstract]
Antidilutive securities excluded from computation (shares)	2,711,333	202,407

Members_ Deficit and Net Loss47

Members’ Deficit and Net Loss per Common and Class B Unit - Distributions Declared (Details) - $ / shares

1 Months Ended

3 Months Ended

Jan. 31, 2016

Dec. 31, 2015

Nov. 30, 2015

Oct. 31, 2015

Sep. 30, 2015

Aug. 31, 2015

Jul. 31, 2015

Jun. 30, 2015

May. 31, 2015

Apr. 30, 2015

Mar. 31, 2015

Feb. 28, 2015

Jan. 31, 2015

Dec. 31, 2014

Mar. 31, 2016

Class of Stock [Line Items]

Preferred Unit, Liquidation Preference Per Share (usd per share)

$ 25

Common Units

Class of Stock [Line Items]

Cash Distributions per Unit (usd per share)

$ 0.03

$ 0.03

$ 0.03

$ 0.1175

$ 0.1175

$ 0.1175

$ 0.1175

$ 0.1175

$ 0.1175

$ 0.1175

$ 0.1175

$ 0.1175

$ 0.1175

$ 0.21

Cash distribution, declaration date

Feb. 18, 2016

Jan. 20, 2016

Dec. 18, 2015

Nov. 20, 2015

Oct. 19, 2015

Sep. 21, 2015

Aug. 20, 2015

Jul. 16, 2015

Jun. 18, 2015

May 19, 2015

Apr. 15, 2015

Mar. 18, 2015

Feb. 17, 2015

Jan. 22, 2015

Cash Distributions Record Date

Mar. 1, 2016

Feb. 1, 2016

Jan. 4, 2016

Dec. 1, 2015

Nov. 2, 2015

Oct. 1, 2015

Sep. 1, 2015

Aug. 3, 2015

Jul. 1, 2015

Jun. 1, 2015

May 1, 2015

Apr. 1, 2015

Mar. 2, 2015

Feb. 2, 2015

Cash Distributions Payment Date

Mar. 15, 2016

Feb. 12, 2016

Jan. 14, 2016

Dec. 15, 2015

Nov. 13, 2015

Oct. 15, 2015

Sep. 14, 2015

Aug. 14, 2015

Jul. 15, 2015

Jun. 12, 2015

May 15, 2015

Apr. 14, 2015

Mar. 17, 2015

Feb. 13, 2015

Series A Preferred Units

Class of Stock [Line Items]

Distribution Rate

7.875%

Preferred Unit, Liquidation Preference Per Share (usd per share)

$ 25

Series B Preferred Unit

Class of Stock [Line Items]

Distribution Rate

7.625%

Preferred Unit, Liquidation Preference Per Share (usd per share)

$ 25

Series C Preferred Units

Class of Stock [Line Items]

Distribution Rate

7.75%

Preferred Unit, Liquidation Preference Per Share (usd per share)

$ 25

Unit-Based Compensation (Detail

Unit-Based Compensation (Details) $ in Millions	3 Months Ended
	Mar. 31, 2016USD ($)officershares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accrued liability | $	$ 0.5
Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	1 year
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	33.33%
Restricted Stock Units (RSUs) | Employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units granted (in units)	7,500
Phantom Share Units (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	33.33%
Phantom Share Units (PSUs) | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units granted (in units)	2,255,033
Phantom Share Units (PSUs) | Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units granted (in units)	125,838
Amended Agreements [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of executives in amended agreements | officer	3

Unit-Based Compensation - Summa

Unit-Based Compensation - Summary of Non-Vested Restricted Units (Details) - Restricted Stock Units (RSUs) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2016	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 9.3
Unrecognized compensation cost recognition period (in years)	1 year 8 months
Number of Non-vested Units
Non-vested units at beginning of period (in units)	976,348
Granted (in units)	7,500
Forfeited (in units)	(8,500)
Vested (in units)	(209,708)
Non-vested units at end of period (in units)	765,640
Weighted Average Grant Date Fair Value
Non-vested units at beginning of period (in dollars per unit)	$ 18.29
Granted (in dollars per unit)	3.11
Forfeited (in dollars per unit)	15.64
Vested (in dollars per unit)	19.37
Non-vested units at end of period (in dollars per unit)	$ 17.88
Selling, General and Administrative Expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 1.3	$ 3.5

Unit-Based Compensation - Sum50

Unit-Based Compensation - Summary of Non-Vested Phantom Units (Details) - Phantom Share Units (PSUs) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2016	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 8.3
Unrecognized compensation cost recognition period (in years)	1 year 5 months
Number of Non-vested Units
Non-vested units at beginning of period (in units)	203,221
Granted (in units)	2,380,871
Forfeited (in units)	(262)
Non-vested units at end of period (in units)	2,583,830
Weighted Average Grant Date Fair Value
Non-vested units at beginning of period (in dollars per unit)	$ 20.99
Granted (in dollars per unit)	2.98
Forfeited (in dollars per unit)	19.62
Non-vested units at end of period (in dollars per unit)	$ 4.39
Selling, General and Administrative Expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-cash compensation	$ 1.1	$ 0.4