Legacy Reserves 10-Q 8 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	7-May-15
Document and Entity Information [Abstract]
Entity Registrant Name	LEGACY RESERVES LP
Entity Central Index Key	1358831
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		69,208,533

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Current assets:
Cash	$3,451	$725
Accounts receivable, net:
Oil and natural gas	38,658	49,390
Joint interest owners	22,108	16,235
Other	259	237
Fair value of derivatives (Notes 6 and 7)	104,541	120,305
Prepaid expenses and other current assets	4,403	5,362
Total current assets	173,420	192,254
Oil and natural gas properties using the successful efforts method, at cost:
Proved properties	2,972,336	2,946,820
Unproved properties	48,159	47,613
Accumulated depletion, depreciation, amortization and impairment	-1,601,883	-1,354,459
Oil and natural gas properties using the successful efforts method, at cost	1,418,612	1,639,974
Other property and equipment, net of accumulated depreciation and amortization of $7,791 and $7,446, respectively	3,560	3,767
Operating rights, net of amortization of $4,620 and $4,509, respectively	2,397	2,508
Fair value of derivatives (Notes 6 and 7)	28,701	32,794
Other assets, net of amortization of $13,243 and $12,551, respectively	25,647	24,255
Investments in equity method investees	3,053	3,054
Total assets	1,655,390	1,898,606
Current liabilities:
Accounts payable	3,069	2,787
Accrued oil and natural gas liabilities (Note 1)	55,352	78,615
Fair value of derivatives (Notes 6 and 7)	1,540	2,080
Asset retirement obligation (Note 8)	3,028	3,028
Other (Notes 2 and 10)	24,204	11,066
Total current liabilities	87,193	97,576
Long-term debt (Note 2)	967,440	938,876
Asset retirement obligation (Note 8)	237,218	223,497
Other long-term liabilities	1,328	1,452
Total liabilities	1,293,179	1,261,401
Commitments and contingencies (Note 5)
Partners' equity (Note 9):
Limited partners' equity - 68,930,150 and 68,910,784 units issued and outstanding at March 31, 2015 and December 31, 2014, respectively	101,952	376,885
General partner's equity (approximately 0.03%)	-8	53
Total partners' equity	362,211	637,205
Total liabilities and partners' equity	1,655,390	1,898,606
Incentive distribution equity - 100,000 units issued and outstanding at March 31, 2015 and December 31, 2014
Partners' equity (Note 9):
Incentive distribution equity - 100,000 units issued and outstanding at March 31, 2015 and December 31, 2014	30,814	30,814
Series A Preferred equity - 2,300,000 units issued and outstanding at March 31, 2015 and December 31, 2014
Partners' equity (Note 9):
Preferred equity	55,192	55,192
Series B Preferred equity - 7,200,000 units issued and outstanding at March 31, 2015 and December 31, 2014
Partners' equity (Note 9):
Preferred equity	$174,261	$174,261

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Other property and equipment, accumulated depreciation and amortization	$7,791	$7,446
Operating rights, amortization	4,620	4,509
Other assets, amortization	$13,243	$12,551
Limited partners' equity, units issued (in shares)	68,930,150	68,910,784
Limited partners' equity, units outstanding (in shares)	68,930,150	68,910,784
General partner's equity, percent	0.03%
Incentive Distribution Equity
Incentive distribution equity, units issued (in shares)	100,000	100,000
Incentive distribution equity, units outstanding (in shares)	100,000	100,000
Preferred Unit Series A
Preferred equity, units issued (in shares)	2,300,000	2,300,000
Preferred equity, units outstanding (in shares)	2,300,000	2,300,000
Preferred Unit Series B
Preferred equity, units issued (in shares)	7,200,000	7,200,000
Preferred equity, units outstanding (in shares)	7,200,000	7,200,000

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenues:
Oil sales	$50,296	$102,055
Natural gas liquids (NGL) sales	4,192	3,965
Natural gas sales	27,051	19,883
Total revenues	81,539	125,903
Expenses:
Oil and natural gas production	49,220	42,534
Production and other taxes	4,218	7,955
General and administrative	8,869	7,647
Depletion, depreciation, amortization and accretion	41,068	33,697
Impairment of long-lived assets	209,402	1,412
Loss on disposal of assets	1,941	2,301
Total expenses	314,718	95,546
Operating income (loss)	-233,179	30,357
Other income (expense):
Interest income	206	223
Interest expense (Notes 2, 6 and 7)	-17,792	-13,939
Equity in income of equity method investees	79	-8
Net gains (losses) on commodity derivatives (Notes 6 and 7)	20,480	-15,886
Other	605	93
Income (loss) before income taxes	-229,601	840
Income tax (expense) benefit	747	-314
Net income (loss)	-228,854	526
Distributions to Preferred unitholders	-4,750	0
Net income (loss) attributable to unitholders	($233,604)	$526
Income (loss) per unit - basic and diluted (Note 9) (in dollars per share)	($3.39)	$0.01
Weighted average number of units used in computing net income (loss) per unit -
Basic (in shares)	68,921	57,309
Diluted (in shares)	68,921	57,367

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Partners' Equity (USD $)	Total	Preferred Equity	Preferred Equity	Preferred Equity	Preferred Equity	Incentive Distribution Equity	Unitholders' Equity	Unitholders' Equity	Unitholders' Equity
In Thousands, except Share data, unless otherwise specified			Limited Partner	Series A Preferred Equity	Series B Preferred Equity			Limited Partner	General Partner
Unitholders equity, beginning balance at Dec. 31, 2014	$637,205			$55,192	$174,261	$30,814		$376,885	$53
Unitholders equity, beginning balance (in shares) at Dec. 31, 2014				2,300,000	7,200,000	100,000		68,911,000
Increase (Decrease) in Partners' Capital [Roll Forward]
Unit-based compensation	976							976
Vesting of restricted and phantom units (in shares)								19,000
Offering costs associated with the issuance of units	-30							-30
Distributions to preferred unitholders & Distributions to common unitholders, $1.185 per unit		-4,750	-4,750				-42,336	-42,336
Net loss	-228,854							-228,793	-61
Unitholders equity, ending balance at Mar. 31, 2015	$362,211			$55,192	$174,261	$30,814		$101,952	($8)
Unitholders equity, ending balance (in shares) at Mar. 31, 2015				2,300,000	7,200,000	100,000		68,930,000

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Partners' Equity (Parenthetical) (Unitholders' Equity, Limited Partner, USD $)	3 Months Ended
	Mar. 31, 2015
Unitholders' Equity | Limited Partner
Distributions to unitholders (in dollars per share)	$0.61

Condensed_Consolidated_Stateme3

Condensed Consolidated Statement of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Cash flows from operating activities:
Net income (loss)	($228,854)	$526
Adjustments to reconcile net income to net cash provided by operating activities:
Depletion, depreciation, amortization and accretion	41,068	33,697
Amortization of debt discount and issuance costs	1,256	1,012
Impairment of long-lived assets	209,402	1,412
(Gain) loss on derivatives	-21,019	15,175
Equity in income of equity method investees	-79	8
Distribution from equity method investee	80	204
Unit-based compensation	981	1
Loss on disposal of assets	1,941	2,301
Changes in assets and liabilities:
(Increase) decrease in accounts receivable, oil and natural gas	10,732	-12,185
(Increase) decrease in accounts receivable, joint interest owners	-5,873	575
(Increase) decrease in accounts receivable, other	-22	97
(Increase) decrease in other assets	318	-41
Increase (decrease) in accrued oil and natural gas liabilities	282	2,131
Increase (decrease) in accrued oil and natural gas liabilities	-23,262	10,711
Increase in other liabilities	10,873	4,545
Total adjustments	226,678	59,643
Net cash provided by (used in) operating activities	-2,176	60,169
Cash flows from investing activities:
Investment in oil and natural gas properties	-15,057	-22,383
Increase in deposits on pending acquisitions	0	-11,200
Proceeds from sale of assets	320	58
Investment in other equipment	-138	-232
Net cash settlements on commodity derivatives	40,337	-3,610
Net cash provided by (used in) investing activities	25,462	-37,367
Cash flows from financing activities:
Proceeds from long-term debt	80,000	126,000
Payments of long-term debt	-52,000	-114,000
Payments of debt issuance costs	-1,444	-58
Offering costs associated with the issuance of units	-30	-105
Distributions to unitholders	-47,086	-34,251
Net cash used in financing activities	-20,560	-22,414
Net increase in cash and cash equivalents	2,726	388
Cash and cash equivalents, beginning of period	725	2,584
Cash and cash equivalents, end of period	3,451	2,972
Non-cash investing and financing activities:
Asset retirement obligations associated with property acquisitions	$11,725	$0

Summary_of_Significant_Account

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies
	(a)	Organization, Basis of Presentation and Description of Business
	Legacy Reserves LP ("LRLP," "Legacy" or the "Partnership") and, unless the context indicates otherwise, its affiliated entities, are referred to as Legacy in these financial statements.
	The accompanying condensed consolidated financial statements have been prepared on the accrual basis of accounting whereby revenues are recognized when earned, and expenses are recognized when incurred. These condensed consolidated financial statements as of March 31, 2015 and for the three months ended March 31, 2015 and 2014 are unaudited. In the opinion of management, such financial statements include the adjustments and accruals, all of which are of a normal recurring nature, which are necessary for a fair presentation of the results for the interim periods. These interim results are not necessarily indicative of results for a full year.
	Certain information and footnote disclosures normally included in the financial statements prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) have been condensed or omitted in this Form 10-Q pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). These condensed consolidated financial statements should be read in connection with the consolidated financial statements and notes thereto included in the Partnership’s Annual Report on Form 10-K for the year ended December 31, 2014.
	LRLP, a Delaware limited partnership, was formed by its general partner, Legacy Reserves GP, LLC (“LRGPLLC”), on October 26, 2005 to own and operate oil and natural gas properties. LRGPLLC is a Delaware limited liability company formed on October 26, 2005, and owns an approximate 0.03% general partner interest in LRLP.
	Significant information regarding rights of unitholders includes the following:
	•Right to receive, within 45 days after the end of each quarter, distributions of available cash, if distributions are declared.
	•No limited partner shall have any management power over LRLP’s business and affairs; the general partner shall conduct, direct and manage LRLP’s activities.
	•The general partner may be removed if such removal is approved by the unitholders holding at least 66 2/3 percent of the outstanding units, including units held by LRGPLLC and its affiliates, provided that a unit majority has elected a successor general partner.
	•Right to receive information reasonably required for tax reporting purposes within 90 days after the close of the calendar year.
	In the event of liquidation, after making required payments to Legacy's preferred unitholders, all property and cash in excess of that required to discharge all liabilities will be distributed to the unitholders and LRGPLLC in proportion to their capital account balances, as adjusted to reflect any gain or loss upon the sale or other disposition of Legacy’s assets in liquidation.
	Legacy owns and operates oil and natural gas producing properties located primarily in the Permian Basin (West Texas and Southeast New Mexico), Rocky Mountain and Mid-Continent regions of the United States.
	(b)	Accrued Oil and Natural Gas Liabilities
	Below are the components of accrued oil and natural gas liabilities as of March 31, 2015 and December 31, 2014:
		March 31,		December 31,
		2015		2014
		(In thousands)
	Revenue payable	$	12,972	$	19,267
	Accrued lease operating expense	19,673		21,177
	Accrued capital expenditures	7,984		20,773
	Accrued ad valorem tax	8,721		9,382
	Other	6,002		8,016
		$	55,352	$	78,615
	(c) Recent Accounting Pronouncements
	In April 2015, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update No. 2015-03, "Simplifying the Presentation of Debt Issuance Costs" ("ASU 2015-03") which changes the presentation of debt issuance costs in financial statements to present such costs as a direct deduction from the related debt liability rather than as an asset. ASU 2015-03 will become effective for public companies during interim and annual reporting periods beginning after December 15, 2015. Early adoption is permitted. We do not expect the adoption of ASU 2015-03 will have a material impact on our consolidated financial statements.

LongTerm_Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt
	Long-term debt consists of the following as of March 31, 2015 and December 31, 2014:
		March 31,			December 31,
		2015			2014
		(In thousands)
	Credit Facility due 2019	$	137,000		$	109,000
	8% Senior Notes due 2020	300,000			300,000
	6.625% Senior Notes due 2021	550,000			550,000
		987,000			959,000
	Unamortized discount on Senior Notes	(19,560		)	(20,124		)
	Total Long-Term Debt	$	967,440		$	938,876
	Credit Facility
	Previous Credit Agreement: On March 10, 2011, Legacy entered into a five-year $1 billion secured revolving credit facility (as amended, the "Previous Credit Agreement"). Borrowings under the Previous Credit Agreement were set to mature on March 10, 2016.
	Current Credit Agreement: On April 1, 2014, Legacy entered into a five-year $1.5 billion secured revolving credit facility with Wells Fargo Bank, National Association, as administrative agent, Compass Bank, as syndication agent, UBS Securities LLC and U.S. Bank National Association, as co-documentation agents and the lenders party thereto (the “Current Credit Agreement”). Borrowings under the Current Credit Agreement mature on April 1, 2019. Legacy's obligations under the Current Credit Agreement are secured by mortgages on over 80% of the total value of its oil and natural gas properties as well as a pledge of all of its ownership interests in its operating subsidiaries. The amount available for borrowing at any one time is limited to the borrowing base and contains a $2 million sub-limit for letters of credit. The borrowing base is currently set at $700 million and was re-affirmed on March 27, 2015. The borrowing base is subject to semi-annual redeterminations on April 1 and October 1 of each year with the next redetermination scheduled for October 1, 2015. Additionally, either Legacy or the lenders may, once during each calendar year, elect to redetermine the borrowing base between scheduled redeterminations. Legacy also has the right, once during each calendar year, to request the redetermination of the borrowing base upon the proposed acquisition of certain oil and natural gas properties where the purchase price is greater than 10% of the borrowing base then in effect. Any increase in the borrowing base requires the consent of all the lenders and any decrease in or maintenance of the borrowing base must be approved by the lenders holding at least 66-2/3% of the outstanding aggregate principal amounts of the loans or participation interests in letters of credit issued under the Current Credit Agreement. If the requisite lenders do not agree on an increase or decrease, then the borrowing base will be the highest borrowing base acceptable to the lenders holding 66-2/3% of the outstanding aggregate principal amounts of the loans or participation interests in letters of credit issued under the Current Credit Agreement so long as it does not increase the borrowing base then in effect. Under the Current Credit Agreement, interest on debt outstanding is charged based on Legacy's selection of a one-, two-, three- or six-month LIBOR rate plus 1.50% to 2.50%, or the ABR which equals the highest of the prime rate, the Federal funds effective rate plus 0.50% or one-month LIBOR plus 1.00%, plus an applicable margin from 0.50% to 1.50% per annum, determined by the percentage of the borrowing base then in effect that is drawn.
	The Current Credit Agreement contains various covenants that limit Legacy's ability to: (i) incur indebtedness, (ii) enter into certain leases, (iii) grant certain liens, (iv) enter into certain swaps, (v) make certain loans, acquisitions, capital expenditures and investments, (vi) make distributions other than from available cash, (vii) merge, consolidate or allow any material change in the character of its business and (viii) engage in certain asset dispositions, including a sale of all or substantially all of its assets. The Current Credit Agreement also contains covenants that, among other things, require Legacy to maintain specified ratios or conditions as follows: (i) secured debt as of the last day of the most recent quarter to EBITDA in total over the last four quarters of not more than 2.5 to 1.0, (ii) as of the last day of the most recent quarter, total EBITDA over the last four quarters to total interest expense over the last four quarters to be greater than 2.5 to 1.0 and (iii) consolidated current assets, as of the last day of the most recent quarter and including the unused amount of the total commitments, to consolidated current liabilities as of the last day of the most recent quarter of not less than 1.0 to 1.0, excluding non-cash assets and liabilities under FASB Accounting Standards Codification 815, which includes the current portion of oil, natural gas and interest rate derivatives.
	As of March 31, 2015, Legacy had approximately $137 million drawn under the Current Credit Agreement at a weighted-average interest rate of 1.79%, leaving approximately $562.9 million of availability under the Current Credit Agreement. For the three-month period ended March 31, 2015, Legacy paid in cash $1.2 million of interest expense on the Current Credit Agreement.
	At March 31, 2015, Legacy was in compliance with all covenants of the Current Credit Agreement.
	8% Senior Notes Due 2020
	On December 4, 2012, Legacy and its 100% owned subsidiary Legacy Reserves Finance Corporation completed a private placement offering to eligible purchasers of an aggregate principal amount of $300 million of our 8% Senior Notes due 2020 (the "2020 Senior Notes"), which were subsequently registered through a public exchange offer that closed on January 8, 2014. The 2020 Senior Notes were issued at 97.848% of par.
	Legacy will have the option to redeem the 2020 Senior Notes, in whole or in part, at any time on or after December 1, 2016, at the specified redemption prices set forth below together with any accrued and unpaid interest, if any, to the date of redemption if redeemed during the twelve-month period beginning on December 1 of the years indicated below.
	Year	Percentage
	2016	104	%
	2017	102	%
	2018 and thereafter	100	%
	Prior to December 1, 2016, Legacy may redeem all or any part of the 2020 Senior Notes at the “make-whole” redemption price as defined in the indenture. In addition, prior to December 1, 2015, Legacy may at its option, redeem up to 35% of the aggregate principal amount of the 2020 Senior Notes at the redemption price of 108% with the net proceeds of a public or private equity offering. Legacy may be required to offer to repurchase the 2020 Senior Notes at a purchase price of 101% of the principal amount, plus accrued and unpaid interest, if any, to the redemption date, in the event of a change of control as defined by the indenture. Legacy's and Legacy Reserves Finance Corporation's obligations under the 2020 Senior Notes are guaranteed by its 100% owned subsidiaries Legacy Reserves Operating GP, LLC, Legacy Reserves Operating LP and Legacy Reserves Services, Inc., which constitute all of Legacy's wholly-owned subsidiaries other than Legacy Reserves Finance Corporation. In the future, the guarantees may be released or terminated under the following circumstances: (i) in connection with any sale or other disposition of all or substantially all of the properties of the guarantor; (ii) in connection with any sale or other disposition of sufficient capital stock of the guarantor so that it no longer qualifies as our Restricted Subsidiary (as defined in the indenture); (iii) if designated to be an unrestricted subsidiary; (iv) upon legal defeasance, covenant defeasance or satisfaction and discharge of the indenture; (v) upon the liquidation or dissolution of the guarantor provided no default or event of default has occurred or is occurring; (vi) at such time the guarantor does not have outstanding guarantees of its, or any other guarantor's, other, debt; or (vii) upon merging into, or transferring all of its properties to Legacy or another guarantor and ceasing to exist. Refer to Note 11 - Subsidiary Guarantors for further details on Legacy's guarantors.
	The indenture governing the 2020 Senior Notes limits Legacy's ability and the ability of certain of its subsidiaries to (i) sell assets; (ii) pay distributions on, repurchase or redeem equity interests or purchase or redeem Legacy's subordinated debt, provided that such subsidiaries may pay dividends to the holders of their equity interests (including Legacy) and Legacy may pay distributions to the holders of its equity interests subject to the absence of certain defaults, the satisfaction of a fixed charge coverage ratio test and so long as the amount of such distributions does not exceed the sum of available cash (as defined in the partnership agreement) at Legacy, net proceeds from the sales of certain securities and return of or reductions to capital from restricted investments; (iii) make certain investments; (iv) incur or guarantee additional indebtedness or issue preferred units; (v) create or incur certain liens; (vi) enter into agreements that restrict distributions or other payments from certain of its subsidiaries to Legacy; (vii) consolidate, merge or transfer all or substantially all of Legacy's assets; (viii) engage in certain transactions with affiliates; (ix) create unrestricted subsidiaries; and (x) engage in certain business activities. These covenants are subject to a number of important exceptions and qualifications. If at any time when the 2020 Senior Notes are rated investment grade by each of Moody's Investors Service, Inc. and Standard & Poor's Ratings Services and no Default (as defined in the indenture) has occurred and is continuing, many of such covenants will terminate and Legacy and its subsidiaries will cease to be subject to such covenants. The indenture also includes customary events of default. The Partnership is in compliance with all financial and other covenants of the 2020 Senior Notes.
	Interest is payable on June 1 and December 1 of each year.
	6.625% Senior Notes Due 2021
	On May 28, 2013, Legacy and its 100% owned subsidiary Legacy Reserves Finance Corporation completed a private placement offering to eligible purchasers of an aggregate principal amount of $250 million of our 6.625% Senior Notes due 2021 (the "2021 Senior Notes"), which were subsequently registered through a public exchange offer that closed on March 18, 2014. The 2021 Senior Notes were issued at 98.405% of par.
	On May 13, 2014, Legacy and its 100% owned subsidiary Legacy Reserves Finance Corporation completed a private placement offering to eligible purchasers of an aggregate principal amount of an additional $300 million of the 6.625% 2021 Senior Notes. These 2021 Senior Notes were issued at 99.0% of par.
	The terms of the 2021 Senior Notes, including details related to our guarantors, are substantially identical to the terms of the 2020 Senior Notes with the exception of the interest rate and redemption provisions noted below. Legacy will have the option to redeem the 2021 Senior Notes, in whole or in part, at any time on or after June 1, 2017, at the specified redemption prices set forth below together with any accrued and unpaid interest, if any, to the date of redemption if redeemed during the twelve-month period beginning on June 1 of the years indicated below.
	Year	Percentage
	2017	103.313	%
	2018	101.656	%
	2019 and thereafter	100	%
	Prior to June 1, 2017, Legacy may redeem all or any part of the 2021 Senior Notes at the “make-whole” redemption price as defined in the indenture. In addition, prior to June 1, 2016, Legacy may at its option, redeem up to 35% of the aggregate principal amount of the 2021 Senior Notes at the redemption price of 106.625% with the net proceeds of a public or private equity offering. Legacy may be required to offer to repurchase the 2021 Senior Notes at a purchase price of 101% of the principal amount, plus accrued and unpaid interest, if any, to the redemption date, in the event of a change of control as defined by the indenture. The Partnership is in compliance with all financial and other covenants of the 2021 Senior Notes.
	Interest is payable on June 1 and December 1 of each year.

Acquisitions

Acquisitions	3 Months Ended
	Mar. 31, 2015
Business Combinations [Abstract]
Acquisitions	Acquisitions
	On June 4, 2014, Legacy purchased a non-operated interest in oil and natural gas properties located in the Piceance Basin in Garfield County, Colorado from WPX Energy Rocky Mountain, LLC , a subsidiary of WPX Energy, Inc., (the "WPX Acquisition") for a net purchase price of $360.0 million. Consideration included both cash and 300,000 Incentive Distribution Units representing limited partner interests in the Partnership (the "Incentive Distribution Units"), 100,000 of which vested immediately and the remainder of which are available to vest and also subject to forfeiture pursuant to the terms of a related Incentive Distribution Unitholder Agreement. This acquisition was accounted for as a business combination. The fully vested Incentive Distribution Units have been reflected in the financial statements at their estimated issuance date fair value of $30.8 million. No value was ascribed to the unvested Incentive Distribution Units upon the closing of the WPX Acquisition as the vesting of the unvested Incentive Distribution Units is dependent upon the consummation of future transactions with WPX and such Incentive Distribution Units will be a portion of the consideration of any such future transactions.
	The allocation of the WPX Acquisition purchase price to the fair value of the acquired assets and liabilities assumed was as follows (in thousands):
	Proved oil and natural gas properties including related equipment	$	403,980
	Future abandonment costs	(43,989		)
	Fair value of net assets acquired	$	359,991
	Pro Forma Operating Results
	The following table reflects the unaudited pro forma results of operations as though the WPX Acquisition had occurred on January 1, 2013. The pro forma amounts are not necessarily indicative of the results that may be reported in the future and do not include any adjustments for acquisition related expenses.
			Three Months Ended March 31,
			2014
	Revenues		$	148,787
	Net income (loss) attributable to unitholders		$	4,116
	Income (loss) per unit — basic and diluted		$	0.07
	Units used in computing income (loss) per unit:
	Basic		57,309
	Diluted		57,367

Related_Party_Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2015
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions
	Cary D. Brown, Chairman of the board of LRGPLLC, Kyle A. McGraw, Director and Executive Vice President and Chief Development Officer of LRGPLLC and Dale Brown, Director of LRGPLLC, own interests in partnerships which, in turn, own a combined non-controlling 4.16% interest as limited partners in a partnership which, until November 10, 2014, owned the building that Legacy occupies. Monthly rent is $65,770, without respect to property taxes and insurance. The lease expires in September 2020.

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies
	From time to time Legacy is a party to various legal proceedings arising in the ordinary course of business. While the outcome of lawsuits cannot be predicted with certainty, Legacy is not currently a party to any proceeding that it believes could have a potential material adverse effect on its financial condition, results of operations or cash flows.
	Legacy is party to a contractual agreement, extending through 2022, to purchase CO2 volumes from a third party. The contract requires Legacy to purchase minimum annual volumes, the pricing of which is calculated as a percentage of NYMEX-WTI oil prices, with a floor of $57.14. Based upon the minimum required volumes and the NYMEX-WTI strip prices as of March 31, 2015, we estimate the value of our total future obligation to be approximately $56.6 million.
	Legacy is subject to numerous laws and regulations governing the discharge of materials into the environment or otherwise relating to environmental protection. To the extent laws are enacted or other governmental action is taken that restricts drilling or imposes environmental protection requirements that result in increased costs to the oil and natural gas industry in general, the business and prospects of Legacy could be adversely affected.
	Legacy has employment agreements with its officers that specify that if the officer is terminated by Legacy for other than cause or following a change in control, the officer shall receive severance pay ranging from 24 to 36 months salary plus bonus and COBRA benefits, respectively.

Fair_Value_Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements
	Fair value is defined as the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value measurements are classified and disclosed in one of the following categories:
	Level 1:	Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities. Legacy considers active markets as those in which transactions for the assets or liabilities occur in sufficient frequency and volume to provide pricing information on an ongoing basis.
	Level 2:	Quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liability. This category includes those derivative instruments that Legacy values using observable market data. Substantially all of these inputs are observable in the marketplace throughout the term of the derivative instrument, can be derived from observable data, or are supported by observable levels at which transactions are executed in the marketplace. Instruments in this category include non-exchange traded derivatives such as over-the-counter commodity price swaps and collars and interest rate swaps as well as long-term incentive plan liabilities calculated using the Black-Scholes model to estimate the fair value as of the measurement date.
	Level 3:	Measured based on prices or valuation models that require inputs that are both significant to the fair value measurement and less observable from objective sources (i.e. supported by little or no market activity). Legacy’s valuation models are primarily industry standard models that consider various inputs including: (a) quoted forward prices for commodities, (b) time value, and (c) current market and contractual prices for the underlying instruments, as well as other relevant economic measures. Level 3 instruments currently are limited to Midland-Cushing crude oil differential swaps. Although Legacy utilizes third party broker quotes to assess the reasonableness of its prices and valuation techniques, Legacy does not have sufficient corroborating evidence to support classifying these assets and liabilities as Level 2.
	Financial assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurement. Legacy’s assessment of the significance of a particular input to the fair value measurement requires judgment, and may affect the valuation of the fair value of assets and liabilities and their placement within the fair value hierarchy levels.
	Fair Value on a Recurring Basis
	The following table sets forth by level within the fair value hierarchy Legacy’s financial assets and liabilities that were accounted for at fair value on a recurring basis as of March 31, 2015:
			Fair Value Measurements at March 31, 2015 Using
			Quoted Prices in Active Markets for Identical Assets			Significant Other Observable Inputs			Significant Unobservable Inputs			Total Carrying Value as of
	Description		(Level 1)			(Level 2)			(Level 3)			March 31, 2015
			(In thousands)
	LTIP liability (a)		$	—		$	(16	)	$	—		$	(16	)
	Oil and natural gas derivatives		—			135,727			(2,485		)	133,242
	Interest rate swaps		—			(1,540		)	—			(1,540		)
	Total		$	—		$	134,171		$	(2,485	)	$	131,686
	(a)	See Note 10 for further discussion on unit-based compensation expenses and the related Long-Term Incentive Plan ("LTIP") liability for certain grants accounted for under the liability method.
	Legacy estimates the fair values of the swaps based on published forward commodity price curves for the underlying commodities as of the date of the estimate for those commodities for which published forward pricing is readily available. For those commodity derivatives for which forward commodity price curves are not readily available, Legacy estimates, with the assistance of third-party pricing experts, the forward curves as of the date of the estimate. Legacy validates the data provided by third parties by understanding the pricing models used, obtaining market values from other pricing sources, analyzing pricing data in certain situations and confirming, where applicable, that those securities trade in active markets. Legacy estimates the option value of puts and calls combined into hedges, including three-way collars and enhanced swaps using an option pricing model which takes into account market volatility, market prices, contract parameters and discount rates based on published LIBOR rates and interest rate swaps. In order to estimate the fair value of our interest rate swaps, Legacy uses a yield curve based on money market rates and interest rate swaps, extrapolates a forecast of future interest rates, estimates each future cash flow, derives discount factors to value the fixed and floating rate cash flows of each swap, and then discounts to present value all known (fixed) and forecasted (floating) swap cash flows. Curve building and discounting techniques used to establish the theoretical market value of interest bearing securities are based on readily available money market rates and interest swap market data. The determination of the fair values above incorporates various factors including the impact of our non-performance risk and the credit standing of the counterparties involved in the Partnership’s derivative contracts. The risk of nonperformance by the Partnership’s counterparties is mitigated by the fact that most of our current counterparties (or their affiliates) are also current or former bank lenders under the Partnership’s revolving credit facility. In addition, Legacy routinely monitors the creditworthiness of its counterparties. As the factors described above are based on significant assumptions made by management, these assumptions are the most sensitive to change.
	The following table sets forth a reconciliation of changes in the fair value of financial assets and liabilities classified as Level 3 in the fair value hierarchy:
			Significant Unobservable Inputs
			(Level 3)
			Three Months Ended
			March 31,
			2015			2014
			(In thousands)
	Beginning balance		$	555		$	20,615
	Total losses		(3,357		)	(6,740		)
	Settlements, net		317			677
	Ending balance		$	(2,485	)	$	14,552
	Losses included in earnings relating to derivatives still held as of March 31, 2015 and 2014		$	(2,485	)	$	(5,622	)
	During periods of market disruption, including periods of volatile oil and natural gas prices, rapid credit contraction or
	illiquidity, it may be difficult to value certain of the Partnership's derivative instruments if trading becomes less frequent and/or
	market data becomes less observable. There may be certain asset classes that were previously in active markets with observable data that become illiquid due to changes in the financial environment. In such cases, more derivative instruments may fall to Level 3 and thus require more subjectivity and management judgment. As such, valuations may include inputs and assumptions that are less observable or require greater estimation as well as valuation methods which are more sophisticated or require greater estimation thereby resulting in valuations with less certainty. Further, rapidly changing commodity and unprecedented credit and equity market conditions could materially impact the valuation of derivative instruments as reported within 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
	Fair Value on a Non-Recurring Basis
	Nonfinancial assets and liabilities measured at fair value on a non-recurring basis include certain nonfinancial assets and liabilities as may be acquired in a business combination and thereby measured at fair value; measurements of oil and natural gas property impairments; and the initial recognition of asset retirement obligations ("ARO") for which fair value is used. These ARO estimates are derived from historical costs as well as management’s expectation of future cost environments. As there is no corroborating market activity to support the assumptions used, Legacy has designated these liabilities as Level 3. A reconciliation of the beginning and ending balances of Legacy’s asset retirement obligation is presented in Note 8.
	Assets measured at fair value during the three-month period ended March 31, 2015 include:
			Fair Value Measurements at March 31, 2015 Using
			Quoted Prices in Active Markets for Identical Assets			Significant Other Observable Inputs			Significant Unobservable Inputs
	Description		(Level 1)			(Level 2)			(Level 3)
			(In thousands)
	Assets:
	Impairment (a)		$	—		$	—		$	198,095
	Acquisitions (b)		$	—		$	—		$	1,691
	(a)	Legacy reviews oil and natural gas properties for impairment when facts and circumstances indicate that their carrying value may not be recoverable. Legacy compares net capitalized costs of proved oil and natural gas properties to estimated undiscounted future net cash flows using management’s expectations of future oil and natural gas prices. These future price scenarios reflect Legacy’s estimation of future price volatility. During the three-month period ended March 31, 2015, Legacy incurred impairment charges of $209.4 million as oil and natural gas properties with a net cost basis of $407.5 million were written down to their fair value of $198.1 million. In order to determine fair value, Legacy compares net capitalized costs of proved oil and natural gas properties to estimated undiscounted future net cash flows using management’s expectations of future oil and natural gas prices. These future price scenarios reflect Legacy’s estimation of future price volatility. If the net capitalized cost exceeds the undiscounted future net cash flows, Legacy writes the net cost basis down to the discounted future net cash flows, which is management's estimate of fair value. Significant inputs used to determine the fair value include estimates of: (i) reserves; (ii) future operating and development costs; (iii) future commodity prices; and (iv) a market-based weighted average cost of capital rate. The underlying commodity prices embedded in the Company's estimated cash flows are the product of a process that begins with NYMEX forward curve pricing, adjusted for estimated location and quality differentials, as well as other factors that Legacy's management believes will impact realizable prices. The inputs used by management for the fair value measurements utilized in this review include significant unobservable inputs, and therefore, the fair value measurements employed are classified as Level 3 for these types of assets.
	(b)	Assets and liabilities acquired in a business combination are recorded at fair value. During the three-month period ended March 31, 2015, Legacy acquired oil and natural gas properties, inclusive of unproved acreage acquisitions, with a fair value of $1.7 million in multiple individually immaterial transactions. Properties acquired are recorded at fair value, which correlates to the discounted future net cash flow. Significant inputs used to determine the fair value include estimates of: (i) reserves; (ii) future operating and development costs; (iii) future commodity prices; and (iv) a market-based weighted average cost of capital rate. The underlying commodity prices embedded in the Company's estimated cash flows are the product of a process that begins with NYMEX forward curve pricing, adjusted for estimated location and quality differentials, as well as other factors that Legacy's management believes will impact realizable prices. For acquired unproved properties, the market-based weighted average cost of capital rate is subjected to additional project specific risking factors. The inputs used by management for the fair value measurements of these acquired oil and natural gas properties include significant unobservable inputs, and therefore, the fair value measurements employed are classified as Level 3 for these types of assets.
	The carrying amount of the revolving long-term debt of $137 million as of March 31, 2015 approximates fair value because Legacy's current borrowing rate does not materially differ from market rates for similar bank borrowings. Legacy has classified the revolving long-term debt as a Level 2 item within the fair value hierarchy. As of March 31, 2015, the fair values of the 2020 Senior Notes and the 2021 Senior Notes were $258.3 million and $434.5 million, respectively. As these valuations are based on unadjusted quoted prices in an active market, the fair values are classified as Level 1 items within the fair value hierarchy.

Derivative_Financial_Instrumen

Derivative Financial Instruments	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments
	Commodity derivative transactions
	Due to the volatility of oil and natural gas prices, Legacy periodically enters into price-risk management transactions (e.g., swaps, enhanced swaps or collars) for a portion of its oil and natural gas production to achieve a more predictable cash flow, as well as to reduce exposure from price fluctuations. While the use of these arrangements limits Legacy’s ability to benefit from increases in the prices of oil and natural gas, it also reduces Legacy’s potential exposure to adverse price movements. Legacy’s arrangements, to the extent it enters into any, apply to only a portion of its production, provide only partial price protection against declines in oil and natural gas prices and limit Legacy’s potential gains from future increases in prices. None of these instruments are used for trading or speculative purposes and required no upfront or deferred cash premium paid or payable to our counterparty.
	All of these price risk management transactions are considered derivative instruments. These derivative instruments are intended to reduce Legacy’s price risk and may be considered hedges for economic purposes, but Legacy has chosen not to designate them as cash flow hedges for accounting purposes. Therefore, all derivative instruments are recorded on the balance sheet at fair value with changes in fair value being recorded in current period earnings.
	By using derivative instruments to mitigate exposures to changes in commodity prices, Legacy exposes itself to credit risk and market risk. Credit risk is the failure of the counterparty to perform under the terms of the derivative contract. When the fair value of a derivative contract is positive, the counterparty owes Legacy, which creates credit risk. Legacy minimizes the credit or repayment risk in derivative instruments by entering into transactions with high-quality counterparties, most of whom are current or former members of Legacy's lending group.
	The following table sets forth a reconciliation of the changes in fair value of Legacy's commodity derivatives for the three months ended March 31, 2015 and 2014:
			Three Months Ended
			March 31,
			2015				2014
			(In thousands)
	Beginning fair value of commodity derivatives		$	153,099			$	17,673
	Total gain (loss) - oil derivatives		13,594				(12,260		)
	Total gain (loss) - natural gas derivatives		6,886				(3,626		)
	Crude oil derivative cash settlements paid (received)		(32,200		)		2,556
	Natural gas derivative cash settlements paid (received)		(8,137		)		1,054
	Ending fair value of commodity derivatives		$	133,242			$	5,397
	Certain of our commodity derivatives and interest rate derivatives are presented on a net basis on the Consolidated Balance Sheets. 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 as of the dates indicated below (in thousands):
			March 31, 2015
			Gross Amounts of Recognized Assets				Gross Amounts Offset in the Consolidated Balance Sheets				Net Amounts Presented in the Consolidated Balance Sheets
	Offsetting Derivative Assets:						(In thousands)
	Commodity derivatives		$	203,594			$	(70,352	)		$	133,242
	Total derivative assets		$	203,594			$	(70,352	)		$	133,242
	Offsetting Derivative Liabilities:
	Commodity derivatives		$	(70,352	)		$	70,352			$	—
	Interest rate derivatives		(1,540		)		—				(1,540		)
	Total derivative liabilities		$	(71,892	)		$	70,352			$	(1,540	)
			December 31, 2014
			Gross Amounts of Recognized Assets				Gross Amounts Offset in the Consolidated Balance Sheets				Net Amounts Presented in the Consolidated Balance Sheets
	Offsetting Derivative Assets:						(In thousands)
	Commodity derivatives		$	223,778			$	(70,679	)		$	153,099
	Total derivative assets		$	223,778			$	(70,679	)		$	153,099
	Offsetting Derivative Liabilities:
	Commodity derivatives		$	(70,679	)		$	70,679			$	—
	Interest rate derivatives		(2,080		)		—				(2,080		)
	Total derivative liabilities		$	(72,759	)		$	70,679			$	(2,080	)
	As of March 31, 2015, Legacy had the following NYMEX West Texas Intermediate ("WTI") crude oil swaps paying floating prices and receiving fixed prices for a portion of its future oil production as indicated below:
					Average
	Time Period		Volumes (Bbls)		Price per Bbl		Price Range per Bbl
	April-December 2015		914,735		$79.14		$52.00	-	$100.20
	2016		228,600		$87.94		$86.30	-	$99.85
	2017		182,500		$84.75		$84.75
	As of March 31, 2015, Legacy had the following Midland-to-Cushing crude oil differential swaps paying a floating differential and receiving a fixed differential for a portion of its future oil production as indicated below:
					Average
	Time Period		Volumes (Bbls)		Price per Bbl		Price Range per Bbl
	April-December 2015		2,475,000		($1.77)		($1.65)	-	($1.90)
	As of March 31, 2015, Legacy had the following NYMEX WTI crude oil derivative three-way collar contracts that combine a long put, a short put and a short call as indicated below:
					Average Short		Average Long		Average Short
	Time Period		Volumes (Bbls)		Put Price per Bbl		Put Price per Bbl		Call Price per Bbl
	April-December 2015		997,400		$64.87		$89.60		$111.39
	2016		621,300		$63.37		$88.37		$106.40
	2017		72,400		$60.00		$85.00		$104.20
	As of March 31, 2015, Legacy had the following NYMEX WTI crude oil enhanced swap contracts that combine a short put, a long put and a fixed-price swap as indicated below:
					Average Long		Average Short		Average
	Time Period		Volumes (Bbls)		Put Price per Bbl		Put Price per Bbl		Swap Price per Bbl
	2016		183,000		$57.00		$82.00		$91.70
	2017		182,500		$57.00		$82.00		$90.85
	2018		127,750		$57.00		$82.00		$90.50
	As of March 31, 2015, Legacy had the following NYMEX WTI crude oil enhanced swap contracts that combine a short put and a fixed-price swap as indicated below:
					Average Short Put		Average Swap
	Time Period		Volumes (Bbls)		Price per Bbl		Price per Bbl
	April-December 2015		688,000		$77.01		$93.79
	As of March 31, 2015, Legacy had the following NYMEX Henry Hub, West Texas Waha, ANR-OK and CIG-Rockies natural gas swaps paying floating natural gas prices and receiving fixed prices for a portion of its future natural gas production as indicated below:
					Average		Price
	Time Period		Volumes (MMBtu)		Price per MMBtu		Range per MMBtu
April-December 2015		13,963,300		$4.39		$3.98	-	$5.82
2016		1,419,200		$4.30		$4.12	-	$5.30
As of March 31, 2015, Legacy had the following NYMEX Henry Hub natural gas derivative three-way collar contracts that combine a long put, a short put and a short call as indicated below:
				Average Short Put		Average Long Put		Average Short Call
Time Period		Volumes (MMBtu)		Price per MMBtu		Price per MMBtu		Price per MMBtu
April-December 2015		6,030,000		$3.66		$4.21		$5.01
2016		5,580,000		$3.75		$4.25		$5.08
2017		5,040,000		$3.75		$4.25		$5.53
As of March 31, 2015, Legacy had the following Henry Hub NYMEX to Northwest Pipeline, NGPL Midcon, California SoCal NGI, San Juan Basin and West Texas WAHA natural gas differential swaps paying a floating differential and receiving a fixed differential for a portion of its future natural gas production as indicated below:
		April-December 2015
				Average
		Volumes (MMBtu)		Price per MMBtu
NWPL		9,000,000		($0.13)
NGPL		360,000		($0.15)
SoCal		180,000		$0.19
San Juan		360,000		($0.12)
WAHA		4,500,000		($0.10)
Interest rate derivative transactions
Due to the volatility of interest rates, Legacy periodically enters into interest rate risk management transactions in the form of interest rate swaps for a portion of its outstanding debt balance. These transactions allow Legacy to reduce exposure to interest rate fluctuations. While the use of these arrangements limits Legacy’s ability to benefit from decreases in interest rates, it also reduces Legacy’s potential exposure to increases in interest rates. Legacy’s arrangements, to the extent it enters into any, apply to only a portion of its outstanding debt balance, provide only partial protection against interest rate increases and limit Legacy’s potential savings from future interest rate declines. It is never management’s intention to hold or issue derivative instruments for speculative trading purposes. Conditions sometimes arise where actual borrowings are less than notional amounts hedged, which has, and could result in overhedged amounts.
Legacy accounts for these interest rate swaps at fair market value and included in the consolidated balance sheet as assets or liabilities.
Legacy does not designate these derivatives as cash flow hedges, even though they reduce its exposure to changes in interest rates. Therefore, the mark-to-market of these instruments is recorded in current earnings as a component of interest expense. The total impact on interest expense from the mark-to-market and settlements was as follows:
		Three Months Ended
		March 31,
		2015				2014
		(In thousands)
Beginning fair value of interest rate swaps		$	(2,080	)		$	(4,759	)
Total loss on interest rate swaps		(148		)		(174		)
Cash settlements paid		688				886
Ending fair value of interest rate swaps		$	(1,540	)		$	(4,047	)
The table below summarizes the interest rate swap position as of March 31, 2015:
											Estimated Fair Market Value at
Notional Amount				Fixed Rate			Effective Date		Maturity Date		March 31, 2015
(Dollars in thousands)
$	29,000			3.07	%		10/16/07		10/16/15		$	(459	)
$	13,000			3.112	%		11/16/07		11/16/15		(235		)
$	12,000			3.131	%		11/28/07		11/28/15		(215		)
$	50,000			2.5	%		10/10/08		10/10/15		(631		)
Total fair market value of interest rate derivatives											$	(1,540	)

Asset_Retirement_Obligation

Asset Retirement Obligation	3 Months Ended
	Mar. 31, 2015
Asset Retirement Obligation [Abstract]
Asset Retirement Obligation	Asset Retirement Obligation
	AROs associated with the retirement of a tangible long-lived asset are recognized as a liability in the period in which it is incurred and becomes determinable. Under this method, when liabilities for dismantlement and abandonment costs, excluding salvage values, are initially recorded, the carrying amount of the related oil and natural gas properties is increased. The fair value of the ARO asset and liability is measured using expected future cash outflows discounted at Legacy’s credit-adjusted risk-free interest rate. Accretion of the liability is recognized each period using the interest method of allocation, and the capitalized cost is depleted over the useful life of the related asset.
	The following table reflects the changes in the ARO during the three months ended March 31, 2015 and year ended December 31, 2014:
		March 31,			December 31,
		2015			2014
		(In thousands)
	Asset retirement obligation - beginning of period	$	226,525		$	175,786
	Liabilities incurred with properties acquired	11,725			50,487
	Liabilities incurred with properties drilled	—			941
	Liabilities settled during the period	(502		)	(2,918		)
	Liabilities associated with properties sold	(19		)	(5,891		)
	Current period accretion	2,517			8,120
	Asset retirement obligation - end of period	$	240,246		$	226,525

Partners_Equity

Partners' Equity	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Partners' Equity	Partners' Equity
	Preferred Units
	On April 17, 2014, Legacy issued 2,000,000 of its 8% Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units (the "Series A Preferred Units") in a public offering at a price of $25.00 per unit. On May 12, 2014 Legacy issued an additional 300,000 Series A Preferred Units pursuant to the underwriters’ option to purchase additional Series A Preferred Units.
	On June 17, 2014, Legacy issued 7,000,000 of its 8.00% Series B Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units (the "Series B Preferred Units") in a public offering at a price of $25.00 per unit. On July 1, 2014, the underwriters exercised their over-allotment option to purchase an additional 200,000 Series B Preferred Units.
	Distributions on the Series A Preferred Units and Series B Preferred Units (collectively, 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 the board of directors of the Partnership's general partner. Distributions on the Series A Preferred Units will be payable from, and including, the date of the original issuance to, but not including April 15, 2024 at an initial rate of 8.00% per annum of the stated liquidation preference. Distributions on the Series B Preferred Units will be payable from, and including, the date of the original issuance to, but not including June 15, 2024 at an initial rate of 8.00% per annum of the stated liquidation preference. Distributions accruing on and after April 15, 2024 for the Series A Preferred Units and June 15, 2024 for the Series B Preferred Units will accrue at an annual rate equal to the sum of (a) three-month LIBOR as calculated on each applicable date of determination and (b) 5.24% for Series A and 5.26% for Series B, based on the $25.00 liquidation preference per preferred unit.
	At any time on or after April 15, 2019 or June 15, 2019, Legacy may redeem the Series A Preferred Units or Series B Preferred Units, respectively, in whole or in part at a redemption price of $25.00 per Preferred Unit plus an amount equal to all accumulated and unpaid distributions thereon through and including the date of redemption, whether or not declared. Legacy may also redeem the Preferred Units in the event of a Change of Control.
	The Series A Preferred Units and the Series B Preferred Units trade on NASDAQ under the symbols "LGCYP" and "LGCYO,” respectively.
	Incentive Distribution Units
	On June 4, 2014, Legacy issued 300,000 Incentive Distribution Units to WPX Energy Rocky Mountain, LLC (“WPX”) as part of the WPX Acquisition. The Incentive Distribution Units issued to WPX include 100,000 Incentive Distribution Units that immediately vested along with the ability to vest in up to an additional 200,000 Incentive Distribution Units (the “Unvested IDUs”) in connection with any future asset sales or transactions completed with Legacy. Incentive Distribution Units that are not issued to WPX or other parties will remain in Legacy's treasury for the benefit of all limited partners until such time as Legacy may make future issuances of Incentive Distribution Units.
	The Incentive Distribution Units represent a right to incremental cash distributions from Legacy after certain target levels of distributions are paid to unitholders, which targets are set above the current levels of Legacy's distributions to unitholders. The Unvested IDUs do not participate in cash distributions from Legacy until vested. The Unvested IDUs will automatically be forfeited on each of the first two anniversaries of the closing date of the WPX Acquisition in an amount per forfeiture equal to 66,666 Incentive Distribution Units and on the third anniversary of the closing date of the WPX Acquisition in an amount equal to 66,668 Incentive Distribution Units. Unvested IDUs that have not been forfeited will vest ratably at a rate of 10,000 Incentive Distribution Units per $35.5 million of additional cash consideration that is paid by Legacy to WPX or to a third party (along with the fair market value of any non-cash consideration) in connection with the consummation of any transaction by which Legacy acquires oil and natural gas properties (or rights therein or other assets related thereto) from WPX or jointly with WPX.
	In addition, the vested and outstanding Incentive Distribution Units held by WPX may be converted by Legacy, subject to applicable conversion factors, into units on a one-for-one basis at any time when Legacy has made a distribution in respect of its units for each of the four full fiscal quarters prior to the delivery of its conversion notice, and the amount of the distribution in respect of the units for the full quarter immediately preceding delivery of its conversion notice was equal to at least $0.90 per unit; and the amount of all distributions during each quarter within the four-quarter period immediately preceding delivery of its conversion notice did not exceed the adjusted operating surplus for such quarter. Further, WPX also has the ability to similarly convert any of its vested Incentive Distribution Units beginning three years after June 4, 2014. WPX may not transfer any of the Incentive Distribution Units it holds to any person that is not a controlled affiliate of WPX.
	Income (loss) per unit
	The following table sets forth the computation of basic and diluted income (loss) per unit:
		Three Months Ended
		March 31,
		2015			2014
		(In thousands)
	Net income (loss)	$	(228,854	)	$	526
	Distributions to preferred unitholders	(4,750		)	—
	Net income (loss) available to unitholders	(233,604		)	526
	Weighted average number of units outstanding	68,921			57,309
	Effect of dilutive securities:
	Restricted and phantom units	—			58
	Weighted average units and potential units outstanding	68,921			57,367
	Basic and diluted income (loss) per unit	$	(3.39	)	$	0.01
	For the three months ended March 31, 2015, 278,383 restricted units and 862,064 phantom units were excluded from the calculation of diluted income per unit due to their anti-dilutive effect. For the three months ended March 31, 2014, 201,643 restricted units and 289,977 phantom units were excluded from the calculation of diluted income per unit due to their anti-dilutive effect.

UnitBased_Compensation

Unit-Based Compensation	3 Months Ended
	Mar. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Unit-Based Compensation	Unit-Based Compensation
	Long-Term Incentive Plan
	On March 15, 2006, the LTIP for Legacy was implemented for its employees, consultants and directors, its affiliates and its general partner. The awards under the LTIP may include unit grants, restricted units, phantom units, unit options and unit appreciation rights ("UARs"). The LTIP permits the grant of awards that may be made or settled in units up to an aggregate of 2,000,000 units. As of March 31, 2015, grants of awards net of forfeitures and, in the case of phantom units, historical exercises covering 1,820,306 units had been made, comprised of 266,014 unit option awards, 561,850 restricted unit awards, 862,064 phantom unit awards and 130,378 unit awards. The UAR awards granted under the LTIP may only be settled in cash, and therefore are not included in the aggregate number of units granted under the LTIP. The LTIP is administered by the compensation committee (the “Compensation Committee”) of the board of directors of LRGPLLC.
	The cost of employee services in exchange for an award of equity instruments is measured based on a grant-date fair value of the award (with limited exceptions), and that cost must generally be recognized over the vesting period of the award. However, if an entity that nominally has the choice of settling awards by issuing stock predominately settles in cash, or if an entity usually settles in cash whenever an employee asks for cash settlement, the entity is settling a substantive liability rather than repurchasing an equity instrument. Due to Legacy’s historical practice of settling options and UARs in cash, Legacy accounts for unit options and UARs by utilizing the liability method. The liability method requires companies to measure the cost of the employee services in exchange for a cash award based on the fair value of the underlying security at the end of each reporting period. Compensation cost is recognized based on the change in the liability between periods.
	Unit Appreciation Rights and Unit Options
	A UAR is a notional unit that entitles the holder, upon vesting, to receive cash valued at the difference between the closing price of units on the exercise date and the exercise price, as determined on the date of grant. Because these awards are settled in cash, Legacy is accounting for the UARs by utilizing the liability method.
	During the year ended December 31, 2014, Legacy issued 136,100 UARs to employees which vest ratably over a three-year period and 105,174 UARs to employees which vest at the end of a three-year period. During the three-month period ended March 31, 2015, Legacy issued 13,500 UARs to employees which vest ratably over a three-year period. All UARs granted in 2014 and 2015 expire seven years from the grant date and are exercisable when they vest.
	For the three-month periods ended March 31, 2015 and 2014, Legacy recorded $5,181 and $(162,916), respectively, of compensation expense (benefit) due to the change in liability from December 31, 2014 and 2013, respectively, based on its use of the Black-Scholes model to estimate the March 31, 2015 and 2014 fair value of these UARs (see Note 6). As of March 31, 2015, there was a total of approximately $12,321 of unrecognized compensation costs related to the unexercised and non-vested portion of these UARs. At March 31, 2015, this cost was expected to be recognized over a weighted-average period of approximately 2.43 years. Compensation expense is based upon the fair value as of March 31, 2015 and is recognized as a percentage of the service period satisfied. Based on historical data, Legacy has assumed a volatility factor of approximately 42% and employed the Black-Scholes model to estimate the March 31, 2015 fair value to be realized as compensation cost based on the percentage of service period satisfied. Based on historical data, Legacy has assumed an estimated forfeiture rate of 4.7%. Legacy will adjust the estimated forfeiture rate based upon actual experience. Legacy has assumed an annual distribution rate of $2.44 per unit. Due to the timing of the valuation, this distribution rate does not reflect the reduced quarterly distribution rate as the reduction was determined subsequent to the period end.
	A summary of UAR and unit option activity for the three months ended March 31, 2015 is as follows:
			Units		Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value
	Outstanding at January 1, 2015		671,229		$	26.97
	Granted		13,500		11.16
	Forfeited		(2,800	)	29.62
	Outstanding at March 31, 2015		681,929		$	26.65	4.9	$	900
	Options and UARs exercisable at March 31, 2015		244,219		$	25.58	3.4	$	—
	The following table summarizes the status of Legacy’s non-vested UARs since January 1, 2015:
			Non-Vested UARs
			Number of Units		Weighted-Average Exercise Price
	Non-vested at January 1, 2015		451,173		$	27.69
	Granted		13,500		11.16
	Vested		(24,163	)	26.36
	Forfeited		(2,800	)	29.62
	Non-vested at March 31, 2015		437,710		$	27.24
	Legacy has used a weighted-average risk-free interest rate of 1.3% in its Black-Scholes calculation of fair value, which approximates the U.S. Treasury interest rates at March 31, 2015 whose terms are consistent with the expected life of the UARs and unit options. Expected life represents the period of time that UARs and unit options are expected to be outstanding and is based on Legacy’s best estimate. The following table represents the weighted-average assumptions used for the Black-Scholes option-pricing model.
		Three Months Ended
		March 31,
		2015
	Expected life (years)	4.94
	Risk free interest rate	1.3	%
	Annual distribution rate per unit	$2.44
	Volatility	42	%
	Phantom Units
	Legacy has also issued phantom units under the LTIP to both executive officers, as described below, and certain other employees. A phantom unit is a notional unit that entitles the holder, upon vesting, to receive one Partnership unit for each phantom unit. Legacy is accounting for these phantom units by utilizing the equity method.
	On September 21, 2009, the board of directors of LRGPLLC, upon the recommendation of the Compensation Committee, implemented an equity-based incentive compensation policy applicable to the executive officers of Legacy. In addition to cash bonus awards, under the compensation plan, the executives are eligible for both subjective and objective grants of phantom units. The subjective, or service-based, grants may be awarded up to a maximum percentage of annual salary as determined by the Compensation Committee. Once granted, these phantom units vest ratably over a three-year period. The objective, or performance-based, grants may be awarded up to a maximum percentage of annual salary as determined by the Compensation Committee. However, the amount to vest each year for the three-year vesting period will be determined on each vesting date based on a three-step process, with the first two steps each comprising 50% of the total vesting amount while the third step is the sum of the first two steps. The first step in the process will be a function of Total Unitholder Return (“TUR”) for the Partnership and the percentage rank of the Legacy TUR among a peer group of upstream master limited partnerships, as determined by the Compensation Committee at the beginning of each year. In the second step, the Legacy TUR will be compared to the TUR of a group of master limited partnerships included in the Alerian MLP Index. The third step is the addition of the above two steps to determine the total performance-based awards to vest. On March 7, 2013, the board of directors of LRGPLLC, upon the recommendation of the Compensation Committee, approved a revised compensation policy (the “Revised Policy”). This Revised Policy applies to incentive awards granted after the fiscal year ended 2013. While the Revised Policy measures TUR against both the peer group and Alerian MLP Index, the measurement periods were increased to a three-year cumulative measurement period with a corresponding increase in vesting from a ratable three-year vesting to three-year cliff vesting. Performance based phantom units subject to vesting which do not vest in a given year will be forfeited. With respect to both the subjective and objective units awarded under both compensation policies, distribution equivalent rights ("DERs") will accumulate and accrue based on the total number of actual amounts vested and will be payable at the date of vesting. However, due to the aforementioned revision for executive employees, accrued DERs paid at the date of vesting will be treated as distributions in the period paid rather than being recognized as compensation expense over the life of the award.
	On March 4, 2014, the Compensation Committee approved the award of 117,197 subjective, or service-based, phantom units and 102,572 objective, or performance based, phantom units to Legacy’s executive officers. On February 24, 2015, the Compensation Committee approved the award of 341,251 subjective, or service-based, phantom units and 259,998 objective, or performance based, phantom units to Legacy’s executive officers.
	Compensation expense related to the phantom units and associated DERs was $0.4 million and $0.3 million for the three months ended March 31, 2015 and 2014, respectively.
	Restricted Units
	During the year ended December 31, 2014, Legacy issued an aggregate of 127,845 restricted units to non-executive employees. These restricted units awarded typically vest ratably over a three-year period all beginning on or around the date of grant. During the three-month period ended March 31, 2015, Legacy issued an aggregate of 28,000 restricted units to non-executive employees. These restricted units awarded vest ratably over a three-year period. Compensation expense related to restricted units was $0.6 million and $0.5 million for the three months ended March 31, 2015 and 2014, respectively. As of March 31, 2015, there was a total of $4.3 million of unrecognized compensation expense related to the unvested portion of these restricted units. At March 31, 2015, this cost was expected to be recognized over a weighted-average period of 2.1 years. Pursuant to the provisions of ASC 718, Legacy’s issued units, as reflected in the accompanying consolidated balance sheet at March 31, 2015, do not include 278,383 units related to unvested restricted unit awards.
	Board Units
	On May 15, 2014, Legacy granted and issued 3,628 units to each of its five non-employee directors. The value of each unit was $27.50 at the time of issuance.

Subsidiary_Guarantors

Subsidiary Guarantors	3 Months Ended
	Mar. 31, 2015
Guarantees [Abstract]
Subsidiary Guarantors	Subsidiary Guarantors
	On April 2, 2014, we filed a registration statement on Form S-3 with the Securities and Exchange Commission ("SEC") to register the issuance and sale of, among other securities, our debt securities, which may be co-issued by Legacy Reserves Finance Corporation. The registration statement also registered guarantees of debt securities by Legacy Reserves Operating GP, LLC, Legacy Reserves Operating LP and Legacy Reserves Services, Inc. The Partnership's 2020 Senior Notes were issued in a private offering on December 4, 2012 and were subsequently registered through a public exchange offer that closed on January 8, 2014. The Partnership's 2021 Senior Notes were issued in two separate private offerings on May 28, 2013 and May 8, 2014. $250 million aggregate principal amount of our 2021 Senior Notes were subsequently registered through a public exchange offer that closed on March 18, 2014. The remaining $300 million of aggregate principal amount of our 2021 Senior Notes were subsequently registered through a public exchange offer that closed on February 10, 2015. The 2020 Senior Notes and the 2021 Senior Notes are guaranteed by our 100% owned subsidiaries Legacy Reserves Operating GP, LLC, Legacy Reserves Operating LP and Legacy Reserves Services, Inc., which constitute all of our wholly-owned subsidiaries other than Legacy Reserves Finance Corporation, and certain other future subsidiaries (the “Guarantors”, together with any future 100% owned subsidiaries that guarantee the Partnership's 2020 Senior Notes and 2021 Senior Notes, the “Subsidiaries”). The Subsidiaries are 100% owned by the Partnership and the guarantees by the Subsidiaries are full and unconditional, except for customary release provisions described in Note 2 - Long-Term Debt. The Partnership has no assets or operations independent of the Subsidiaries, and there are no significant restrictions upon the ability of the Subsidiaries to distribute funds to the Partnership. The guarantees constitute joint and several obligations of the Guarantors.

Subsequent_Events

Subsequent Events	3 Months Ended
	Mar. 31, 2015
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events
	On April 16, 2015, Legacy’s board of directors approved a distribution of $0.35 per unit payable on May 15, 2015 to unitholders of record on May 1, 2015.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Accounting	The accompanying condensed consolidated financial statements have been prepared on the accrual basis of accounting whereby revenues are recognized when earned, and expenses are recognized when incurred. These condensed consolidated financial statements as of March 31, 2015 and for the three months ended March 31, 2015 and 2014 are unaudited. In the opinion of management, such financial statements include the adjustments and accruals, all of which are of a normal recurring nature, which are necessary for a fair presentation of the results for the interim periods. These interim results are not necessarily indicative of results for a full year.
	Certain information and footnote disclosures normally included in the financial statements prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) have been condensed or omitted in this Form 10-Q pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). These condensed consolidated financial statements should be read in connection with the consolidated financial statements and notes thereto included in the Partnership’s Annual Report on Form 10-K for the year ended December 31, 2014.
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	In April 2015, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update No. 2015-03, "Simplifying the Presentation of Debt Issuance Costs" ("ASU 2015-03") which changes the presentation of debt issuance costs in financial statements to present such costs as a direct deduction from the related debt liability rather than as an asset. ASU 2015-03 will become effective for public companies during interim and annual reporting periods beginning after December 15, 2015. Early adoption is permitted. We do not expect the adoption of ASU 2015-03 will have a material impact on our consolidated financial statements.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of components of accrued oil and natural gas liabilities	Below are the components of accrued oil and natural gas liabilities as of March 31, 2015 and December 31, 2014:
		March 31,		December 31,
		2015		2014
		(In thousands)
	Revenue payable	$	12,972	$	19,267
	Accrued lease operating expense	19,673		21,177
	Accrued capital expenditures	7,984		20,773
	Accrued ad valorem tax	8,721		9,382
	Other	6,002		8,016
		$	55,352	$	78,615

LongTerm_Debt_Tables

Long-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Schedule of long-term debt	Long-term debt consists of the following as of March 31, 2015 and December 31, 2014:
		March 31,			December 31,
		2015			2014
		(In thousands)
	Credit Facility due 2019	$	137,000		$	109,000
	8% Senior Notes due 2020	300,000			300,000
	6.625% Senior Notes due 2021	550,000			550,000
		987,000			959,000
	Unamortized discount on Senior Notes	(19,560		)	(20,124		)
	Total Long-Term Debt	$	967,440		$	938,876
Schedule of debt redemption	Legacy will have the option to redeem the 2020 Senior Notes, in whole or in part, at any time on or after December 1, 2016, at the specified redemption prices set forth below together with any accrued and unpaid interest, if any, to the date of redemption if redeemed during the twelve-month period beginning on December 1 of the years indicated below.
	Year	Percentage
	2016	104	%
	2017	102	%
	2018 and thereafter	100	%
	Legacy will have the option to redeem the 2021 Senior Notes, in whole or in part, at any time on or after June 1, 2017, at the specified redemption prices set forth below together with any accrued and unpaid interest, if any, to the date of redemption if redeemed during the twelve-month period beginning on June 1 of the years indicated below.
	Year	Percentage
	2017	103.313	%
	2018	101.656	%
	2019 and thereafter	100	%

Acquisitions_Tables

Acquisitions (Tables)	3 Months Ended
	Mar. 31, 2015
Business Combinations [Abstract]
Schedule of allocation of the purchase price to the fair value of the acquired assets and liabilities assumed	The allocation of the WPX Acquisition purchase price to the fair value of the acquired assets and liabilities assumed was as follows (in thousands):
	Proved oil and natural gas properties including related equipment	$	403,980
	Future abandonment costs	(43,989		)
	Fair value of net assets acquired	$	359,991
Schedule of unaudited pro forma results of operations	The following table reflects the unaudited pro forma results of operations as though the WPX Acquisition had occurred on January 1, 2013. The pro forma amounts are not necessarily indicative of the results that may be reported in the future and do not include any adjustments for acquisition related expenses.
			Three Months Ended March 31,
			2014
	Revenues		$	148,787
	Net income (loss) attributable to unitholders		$	4,116
	Income (loss) per unit — basic and diluted		$	0.07
	Units used in computing income (loss) per unit:
	Basic		57,309
	Diluted		57,367

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis	The following table sets forth by level within the fair value hierarchy Legacy’s financial assets and liabilities that were accounted for at fair value on a recurring basis as of March 31, 2015:
			Fair Value Measurements at March 31, 2015 Using
			Quoted Prices in Active Markets for Identical Assets			Significant Other Observable Inputs			Significant Unobservable Inputs			Total Carrying Value as of
	Description		(Level 1)			(Level 2)			(Level 3)			March 31, 2015
			(In thousands)
	LTIP liability (a)		$	—		$	(16	)	$	—		$	(16	)
	Oil and natural gas derivatives		—			135,727			(2,485		)	133,242
	Interest rate swaps		—			(1,540		)	—			(1,540		)
	Total		$	—		$	134,171		$	(2,485	)	$	131,686
	(a)	See Note 10 for further discussion on unit-based compensation expenses and the related Long-Term Incentive Plan ("LTIP") liability for certain grants accounted for under the liability method.
Reconciliation of changes in the fair value of financial assets and liabilities classified as Level 3	The following table sets forth a reconciliation of changes in the fair value of financial assets and liabilities classified as Level 3 in the fair value hierarchy:
			Significant Unobservable Inputs
			(Level 3)
			Three Months Ended
			March 31,
			2015			2014
			(In thousands)
	Beginning balance		$	555		$	20,615
	Total losses		(3,357		)	(6,740		)
	Settlements, net		317			677
	Ending balance		$	(2,485	)	$	14,552
	Losses included in earnings relating to derivatives still held as of March 31, 2015 and 2014		$	(2,485	)	$	(5,622	)
Schedule of fair value measurements of proved oil and natural gas properties	Assets measured at fair value during the three-month period ended March 31, 2015 include:
			Fair Value Measurements at March 31, 2015 Using
			Quoted Prices in Active Markets for Identical Assets			Significant Other Observable Inputs			Significant Unobservable Inputs
	Description		(Level 1)			(Level 2)			(Level 3)
			(In thousands)
	Assets:
	Impairment (a)		$	—		$	—		$	198,095
	Acquisitions (b)		$	—		$	—		$	1,691
	(a)	Legacy reviews oil and natural gas properties for impairment when facts and circumstances indicate that their carrying value may not be recoverable. Legacy compares net capitalized costs of proved oil and natural gas properties to estimated undiscounted future net cash flows using management’s expectations of future oil and natural gas prices. These future price scenarios reflect Legacy’s estimation of future price volatility. During the three-month period ended March 31, 2015, Legacy incurred impairment charges of $209.4 million as oil and natural gas properties with a net cost basis of $407.5 million were written down to their fair value of $198.1 million. In order to determine fair value, Legacy compares net capitalized costs of proved oil and natural gas properties to estimated undiscounted future net cash flows using management’s expectations of future oil and natural gas prices. These future price scenarios reflect Legacy’s estimation of future price volatility. If the net capitalized cost exceeds the undiscounted future net cash flows, Legacy writes the net cost basis down to the discounted future net cash flows, which is management's estimate of fair value. Significant inputs used to determine the fair value include estimates of: (i) reserves; (ii) future operating and development costs; (iii) future commodity prices; and (iv) a market-based weighted average cost of capital rate. The underlying commodity prices embedded in the Company's estimated cash flows are the product of a process that begins with NYMEX forward curve pricing, adjusted for estimated location and quality differentials, as well as other factors that Legacy's management believes will impact realizable prices. The inputs used by management for the fair value measurements utilized in this review include significant unobservable inputs, and therefore, the fair value measurements employed are classified as Level 3 for these types of assets.
	(b)	Assets and liabilities acquired in a business combination are recorded at fair value. During the three-month period ended March 31, 2015, Legacy acquired oil and natural gas properties, inclusive of unproved acreage acquisitions, with a fair value of $1.7 million in multiple individually immaterial transactions. Properties acquired are recorded at fair value, which correlates to the discounted future net cash flow. Significant inputs used to determine the fair value include estimates of: (i) reserves; (ii) future operating and development costs; (iii) future commodity prices; and (iv) a market-based weighted average cost of capital rate. The underlying commodity prices embedded in the Company's estimated cash flows are the product of a process that begins with NYMEX forward curve pricing, adjusted for estimated location and quality differentials, as well as other factors that Legacy's management believes will impact realizable prices. For acquired unproved properties, the market-based weighted average cost of capital rate is subjected to additional project specific risking factors. The inputs used by management for the fair value measurements of these acquired oil and natural gas properties include significant unobservable inputs, and therefore, the fair value measurements employed are classified as Level 3 for these types of assets.

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of reconciliation of the changes in fair value of Legacy's commodity derivatives	The following table sets forth a reconciliation of the changes in fair value of Legacy's commodity derivatives for the three months ended March 31, 2015 and 2014:
			Three Months Ended
			March 31,
			2015				2014
			(In thousands)
	Beginning fair value of commodity derivatives		$	153,099			$	17,673
	Total gain (loss) - oil derivatives		13,594				(12,260		)
	Total gain (loss) - natural gas derivatives		6,886				(3,626		)
	Crude oil derivative cash settlements paid (received)		(32,200		)		2,556
	Natural gas derivative cash settlements paid (received)		(8,137		)		1,054
	Ending fair value of commodity derivatives		$	133,242			$	5,397
Schedule of gross fair values of our derivative instruments, presenting the impact of offsetting the derivative assets and liabilities	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 as of the dates indicated below (in thousands):
			March 31, 2015
			Gross Amounts of Recognized Assets				Gross Amounts Offset in the Consolidated Balance Sheets				Net Amounts Presented in the Consolidated Balance Sheets
	Offsetting Derivative Assets:						(In thousands)
	Commodity derivatives		$	203,594			$	(70,352	)		$	133,242
	Total derivative assets		$	203,594			$	(70,352	)		$	133,242
	Offsetting Derivative Liabilities:
	Commodity derivatives		$	(70,352	)		$	70,352			$	—
	Interest rate derivatives		(1,540		)		—				(1,540		)
	Total derivative liabilities		$	(71,892	)		$	70,352			$	(1,540	)
			December 31, 2014
			Gross Amounts of Recognized Assets				Gross Amounts Offset in the Consolidated Balance Sheets				Net Amounts Presented in the Consolidated Balance Sheets
	Offsetting Derivative Assets:						(In thousands)
	Commodity derivatives		$	223,778			$	(70,679	)		$	153,099
	Total derivative assets		$	223,778			$	(70,679	)		$	153,099
	Offsetting Derivative Liabilities:
	Commodity derivatives		$	(70,679	)		$	70,679			$	—
	Interest rate derivatives		(2,080		)		—				(2,080		)
	Total derivative liabilities		$	(72,759	)		$	70,679			$	(2,080	)
Schedule of notional amounts of outstanding derivative positions	As of March 31, 2015, Legacy had the following NYMEX West Texas Intermediate ("WTI") crude oil swaps paying floating prices and receiving fixed prices for a portion of its future oil production as indicated below:
					Average
	Time Period		Volumes (Bbls)		Price per Bbl		Price Range per Bbl
	April-December 2015		914,735		$79.14		$52.00	-	$100.20
	2016		228,600		$87.94		$86.30	-	$99.85
	2017		182,500		$84.75		$84.75
	As of March 31, 2015, Legacy had the following Midland-to-Cushing crude oil differential swaps paying a floating differential and receiving a fixed differential for a portion of its future oil production as indicated below:
					Average
	Time Period		Volumes (Bbls)		Price per Bbl		Price Range per Bbl
	April-December 2015		2,475,000		($1.77)		($1.65)	-	($1.90)
	As of March 31, 2015, Legacy had the following NYMEX WTI crude oil derivative three-way collar contracts that combine a long put, a short put and a short call as indicated below:
					Average Short		Average Long		Average Short
	Time Period		Volumes (Bbls)		Put Price per Bbl		Put Price per Bbl		Call Price per Bbl
	April-December 2015		997,400		$64.87		$89.60		$111.39
	2016		621,300		$63.37		$88.37		$106.40
	2017		72,400		$60.00		$85.00		$104.20
	As of March 31, 2015, Legacy had the following NYMEX WTI crude oil enhanced swap contracts that combine a short put, a long put and a fixed-price swap as indicated below:
					Average Long		Average Short		Average
	Time Period		Volumes (Bbls)		Put Price per Bbl		Put Price per Bbl		Swap Price per Bbl
	2016		183,000		$57.00		$82.00		$91.70
	2017		182,500		$57.00		$82.00		$90.85
	2018		127,750		$57.00		$82.00		$90.50
	As of March 31, 2015, Legacy had the following NYMEX WTI crude oil enhanced swap contracts that combine a short put and a fixed-price swap as indicated below:
					Average Short Put		Average Swap
	Time Period		Volumes (Bbls)		Price per Bbl		Price per Bbl
	April-December 2015		688,000		$77.01		$93.79
	As of March 31, 2015, Legacy had the following NYMEX Henry Hub, West Texas Waha, ANR-OK and CIG-Rockies natural gas swaps paying floating natural gas prices and receiving fixed prices for a portion of its future natural gas production as indicated below:
					Average		Price
	Time Period		Volumes (MMBtu)		Price per MMBtu		Range per MMBtu
	April-December 2015		13,963,300		$4.39		$3.98	-	$5.82
	2016		1,419,200		$4.30		$4.12	-	$5.30
	As of March 31, 2015, Legacy had the following NYMEX Henry Hub natural gas derivative three-way collar contracts that combine a long put, a short put and a short call as indicated below:
					Average Short Put		Average Long Put		Average Short Call
	Time Period		Volumes (MMBtu)		Price per MMBtu		Price per MMBtu		Price per MMBtu
	April-December 2015		6,030,000		$3.66		$4.21		$5.01
	2016		5,580,000		$3.75		$4.25		$5.08
	2017		5,040,000		$3.75		$4.25		$5.53
	As of March 31, 2015, Legacy had the following Henry Hub NYMEX to Northwest Pipeline, NGPL Midcon, California SoCal NGI, San Juan Basin and West Texas WAHA natural gas differential swaps paying a floating differential and receiving a fixed differential for a portion of its future natural gas production as indicated below:
			April-December 2015
					Average
			Volumes (MMBtu)		Price per MMBtu
	NWPL		9,000,000		($0.13)
	NGPL		360,000		($0.15)
	SoCal		180,000		$0.19
	San Juan		360,000		($0.12)
	WAHA		4,500,000		($0.10)
Schedule of total impact on interest expense from the mark-to-market and settlements	The total impact on interest expense from the mark-to-market and settlements was as follows:
			Three Months Ended
			March 31,
			2015				2014
			(In thousands)
	Beginning fair value of interest rate swaps		$	(2,080	)		$	(4,759	)
	Total loss on interest rate swaps		(148		)		(174		)
	Cash settlements paid		688				886
	Ending fair value of interest rate swaps		$	(1,540	)		$	(4,047	)
Schedule of interest rate swap liabilities	The table below summarizes the interest rate swap position as of March 31, 2015:
												Estimated Fair Market Value at
	Notional Amount				Fixed Rate			Effective Date		Maturity Date		March 31, 2015
	(Dollars in thousands)
	$	29,000			3.07	%		10/16/07		10/16/15		$	(459	)
	$	13,000			3.112	%		11/16/07		11/16/15		(235		)
	$	12,000			3.131	%		11/28/07		11/28/15		(215		)
	$	50,000			2.5	%		10/10/08		10/10/15		(631		)
	Total fair market value of interest rate derivatives											$	(1,540	)

Asset_Retirement_Obligation_Ta

Asset Retirement Obligation (Tables)	3 Months Ended
	Mar. 31, 2015
Asset Retirement Obligation [Abstract]
Schedule of changes in asset retirement obligations	The following table reflects the changes in the ARO during the three months ended March 31, 2015 and year ended December 31, 2014:
		March 31,			December 31,
		2015			2014
		(In thousands)
	Asset retirement obligation - beginning of period	$	226,525		$	175,786
	Liabilities incurred with properties acquired	11,725			50,487
	Liabilities incurred with properties drilled	—			941
	Liabilities settled during the period	(502		)	(2,918		)
	Liabilities associated with properties sold	(19		)	(5,891		)
	Current period accretion	2,517			8,120
	Asset retirement obligation - end of period	$	240,246		$	226,525

Partners_Equity_Tables

Partners' Equity (Tables)	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Schedule of computation of basic and diluted income (loss) per unit	The following table sets forth the computation of basic and diluted income (loss) per unit:
		Three Months Ended
		March 31,
		2015			2014
		(In thousands)
	Net income (loss)	$	(228,854	)	$	526
	Distributions to preferred unitholders	(4,750		)	—
	Net income (loss) available to unitholders	(233,604		)	526
	Weighted average number of units outstanding	68,921			57,309
	Effect of dilutive securities:
	Restricted and phantom units	—			58
	Weighted average units and potential units outstanding	68,921			57,367
	Basic and diluted income (loss) per unit	$	(3.39	)	$	0.01

UnitBased_Compensation_Tables

Unit-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of option and UAR activity	A summary of UAR and unit option activity for the three months ended March 31, 2015 is as follows:
			Units		Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value
	Outstanding at January 1, 2015		671,229		$	26.97
	Granted		13,500		11.16
	Forfeited		(2,800	)	29.62
	Outstanding at March 31, 2015		681,929		$	26.65	4.9	$	900
	Options and UARs exercisable at March 31, 2015		244,219		$	25.58	3.4	$	—
Schedule of status of the Partnershipbs non-vested UARs	The following table summarizes the status of Legacy’s non-vested UARs since January 1, 2015:
			Non-Vested UARs
			Number of Units		Weighted-Average Exercise Price
	Non-vested at January 1, 2015		451,173		$	27.69
	Granted		13,500		11.16
	Vested		(24,163	)	26.36
	Forfeited		(2,800	)	29.62
	Non-vested at March 31, 2015		437,710		$	27.24
Schedule of weighted average assumptions used for the Black-Scholes option-pricing model	The following table represents the weighted-average assumptions used for the Black-Scholes option-pricing model.
		Three Months Ended
		March 31,
		2015
	Expected life (years)	4.94
	Risk free interest rate	1.3	%
	Annual distribution rate per unit	$2.44
	Volatility	42	%

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Other Narrative (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General partner's equity, percent	0.03%	0.03%
Term of right to receive distributions of available cash after quarter end	45 days
Minimum percentage of unitholder approval to remove general partner	66.67%
Term of right to receive information reasonably required for tax reporting purposes after close of year	90 days

Summary_of_Significant_Account4

Summary of Significant Accounting Policies - Accrued Oil and Natural Gas Liabilities (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Revenue payable	$12,972	$19,267
Accrued lease operating expense	19,673	21,177
Accrued capital expenditures	7,984	20,773
Accrued ad valorem tax	8,721	9,382
Other	6,002	8,016
Accrued oil and natural gas liabilities	$55,352	$78,615

LongTerm_Debt_Schedule_of_Long

Long-Term Debt - Schedule of Long-term Debt (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014	13-May-14	28-May-13
In Thousands, unless otherwise specified
Debt Instrument [Line Items]
Long-term debt, gross	$987,000	$959,000
Unamortized discount on Senior Notes	-19,560	-20,124
Total Long-Term Debt	967,440	938,876
Senior notes | 8% Senior Notes due 2020
Debt Instrument [Line Items]
Stated interest rate	8.00%
Long-term debt, gross	300,000	300,000
Senior notes | 6.625% Senior Notes due 2021
Debt Instrument [Line Items]
Stated interest rate	6.63%
Long-term debt, gross	550,000	550,000	300,000	250,000
Credit facility due 2019
Debt Instrument [Line Items]
Long-term debt, gross	$137,000	$109,000

LongTerm_Debt_Credit_Facility_

Long-Term Debt - Credit Facility (Details) (USD $)	0 Months Ended		3 Months Ended
	Mar. 10, 2011	Apr. 02, 2014	Mar. 31, 2015	Dec. 31, 2014	Mar. 27, 2015
Line of Credit Facility [Line Items]
Long-term debt, gross			$987,000,000	$959,000,000
Credit Facility due 2016
Line of Credit Facility [Line Items]
Expiration period	5 years
Current borrowing capacity	1,000,000,000
Credit facility due 2019
Line of Credit Facility [Line Items]
Expiration period		5 years
Maximum borrowing capacity		1,500,000,000			700,000,000
Minimum percent of total value securing credit agreement		80.00%
Purchase price of properties as a percentage of borrowing base required for potential re-determination of borrowing base, minimum		10.00%
Minimum percent of outstanding principal amount required for changes to credit agreement		66.67%
Long-term debt, gross			137,000,000	109,000,000
Interest rate at period end			1.79%
Remaining borrowing capacity			562,900,000
Interest Paid			1,200,000
Credit facility due 2019 | Maximum
Line of Credit Facility [Line Items]
Ratio of indebtedness to EBITDA			2.5
Credit facility due 2019 | Minimum
Line of Credit Facility [Line Items]
Ratio of indebtedness to EBITDA				2.5
Credit facility due 2019 | one-, two-, three- or six-month LIBOR [Member] | Maximum
Line of Credit Facility [Line Items]
Basis spread on variable rate		2.50%
Credit facility due 2019 | one-, two-, three- or six-month LIBOR [Member] | Minimum
Line of Credit Facility [Line Items]
Basis spread on variable rate		1.50%
Credit facility due 2019 | Alternate Base Rate, Federal Funds [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate		0.50%
Credit facility due 2019 | Alternate Base Rate, one-month LIBOR [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate		1.00%
Credit facility due 2019 | Standard Alternate Base Rate [Member] | Maximum
Line of Credit Facility [Line Items]
Basis spread on variable rate		1.50%
Credit facility due 2019 | Standard Alternate Base Rate [Member] | Minimum
Line of Credit Facility [Line Items]
Basis spread on variable rate		0.50%
Letter of Credit [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$2,000,000

LongTerm_Debt_Senior_Notes_Det

Long-Term Debt - Senior Notes (Details) (USD $)	3 Months Ended	12 Months Ended	0 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2013	13-May-14	28-May-13	Dec. 04, 2012	Dec. 31, 2014
Debt Instrument [Line Items]
Long-term debt, gross	987,000					$959,000
Senior notes | 8% Senior Notes due 2020
Debt Instrument [Line Items]
Stated interest rate	8.00%
Long-term debt, gross	300,000					300,000
Issuance percent of par					97.85%
Percent of notes eligible of early redemption						35.00%
Senior notes | 8% Senior Notes due 2020 | Company Option [Member]
Debt Instrument [Line Items]
Redemption price percentage	108.00%
Senior notes | 8% Senior Notes due 2020 | Change in Control [Member]
Debt Instrument [Line Items]
Redemption price percentage		101.00%
Senior notes | 8% Senior Notes due 2020 | 2016
Debt Instrument [Line Items]
Redemption price percentage	104.00%
Senior notes | 8% Senior Notes due 2020 | 2017
Debt Instrument [Line Items]
Redemption price percentage	102.00%
Senior notes | 8% Senior Notes due 2020 | 2018 and thereafter
Debt Instrument [Line Items]
Redemption price percentage	100.00%
Senior notes | 6.625% Senior Notes due 2021
Debt Instrument [Line Items]
Stated interest rate	6.63%
Long-term debt, gross	550,000		300,000	250,000		$550,000
Issuance percent of par			99.00%	98.41%
Percent of notes eligible of early redemption	35.00%
Senior notes | 6.625% Senior Notes due 2021 | Company Option [Member]
Debt Instrument [Line Items]
Redemption price percentage	106.63%
Senior notes | 6.625% Senior Notes due 2021 | Change in Control [Member]
Debt Instrument [Line Items]
Redemption price percentage	101.00%
Senior notes | 6.625% Senior Notes due 2021 | 2017
Debt Instrument [Line Items]
Redemption price percentage	103.31%
Senior notes | 6.625% Senior Notes due 2021 | 2018
Debt Instrument [Line Items]
Redemption price percentage	101.66%
Senior notes | 6.625% Senior Notes due 2021 | 2019 and thereafter
Debt Instrument [Line Items]
Redemption price percentage	100.00%
Legacy Reserves Finance Corporation
Debt Instrument [Line Items]
Ownership interest			100.00%	100.00%	100.00%

Acquisitions_Details

Acquisitions (Details) (USD $)	3 Months Ended	0 Months Ended	3 Months Ended
	Mar. 31, 2015	Jun. 04, 2014	Mar. 31, 2014	Jun. 03, 2014
Incentive Distribution Equity
Business Acquisition [Line Items]
Incentive Distribution Units issued in exchange for oil and natural gas properties	$30,800,000
WPX acquisition
Business Acquisition [Line Items]
Acquisition purchase price		360,000,000
Equity interests issuable (in shares)		300,000
Schedule of allocation of the purchase price to the fair value of the acquired assets and liabilities assumed
Proved oil and natural gas properties including related equipment				403,980,000
Future abandonment costs				-43,989,000
Fair value of net assets acquired				359,991,000
Pro Forma Operating Results
Revenues			148,787,000
Net income (loss) attributable to unitholders			$4,116,000
Income (loss) per unit - basic and diluted (in dollars per share)			$0.07
Basic (in shares)			57,309,000
Diluted (in shares)			57,367,000
WPX acquisition | Immediate vesting
Business Acquisition [Line Items]
Equity interests issuable (in shares)		100,000

Related_Party_Transactions_Det

Related Party Transactions (Details) (President/CEO and Director, EVP, CDO, USD $)	3 Months Ended
	Mar. 31, 2015
President/CEO and Director, EVP, CDO
Related Party Transaction [Line Items]
Noncontrolling ownership interest in third party by related party	4.16%
Monthly rent expense	$65,770

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015
Loss Contingencies [Line Items]
Purchase obligation calculated floor price	57.14
Estimated total future purchase obligation	56.6
Officer
Loss Contingencies [Line Items]
Employment agreements with officers, severance pay consideration period, minimum	24 months
Employment agreements with officers, severance pay consideration period, maximum	36 months

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	13-May-14	28-May-13
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Impairment	$1,418,612,000		$1,639,974,000
Impairment of long-lived assets	209,400,000
Long-term debt, gross	987,000,000		959,000,000
Credit facility due 2019
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Long-term debt, gross	137,000,000		109,000,000
Senior notes | 8% Senior Notes due 2020
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Long-term debt, gross	300,000,000		300,000,000
Senior notes | 6.625% Senior Notes due 2021
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Long-term debt, gross	550,000,000		550,000,000	300,000,000	250,000,000
Quoted Prices in Active Markets for Identical Assets (Level 1) | Senior notes | 8% Senior Notes due 2020
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Fair value of notes payable	258,300,000
Quoted Prices in Active Markets for Identical Assets (Level 1) | Senior notes | 6.625% Senior Notes due 2021
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Fair value of notes payable	434,500,000
Recurring
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
LTIP liability	-16,000
Fair value of assets (liabilities)	131,686,000
Recurring | Commodity derivatives | Oil and natural gas
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Derivative asset	133,242,000
Recurring | Interest rate swaps
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Derivative liability	-1,540,000
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
LTIP liability	0
Fair value of assets (liabilities)	0
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Commodity derivatives | Oil and natural gas
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Derivative asset	0
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Interest rate swaps
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Derivative liability	0
Recurring | Significant Other Observable Inputs (Level 2)
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
LTIP liability	-16,000
Fair value of assets (liabilities)	134,171,000
Recurring | Significant Other Observable Inputs (Level 2) | Commodity derivatives | Oil and natural gas
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Derivative asset	135,727,000
Recurring | Significant Other Observable Inputs (Level 2) | Interest rate swaps
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Derivative liability	-1,540,000
Recurring | Significant Unobservable Inputs (Level 3)
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
LTIP liability	0
Fair value of assets (liabilities)	-2,485,000
Reconciliation of changes in the fair value of financial assets and liabilities classified as Level 3
Beginning balance	555,000	20,615,000
Total losses	-3,357,000	-6,740,000
Settlements, net	317,000	677,000
Ending balance	-2,485,000	14,552,000
Recurring | Significant Unobservable Inputs (Level 3) | Derivative assets
Reconciliation of changes in the fair value of financial assets and liabilities classified as Level 3
Losses included in earnings relating to derivatives still held as of March 31, 2015 and 2014	-2,485,000	-5,622,000
Recurring | Significant Unobservable Inputs (Level 3) | Commodity derivatives | Oil and natural gas
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Derivative asset	-2,485,000
Recurring | Significant Unobservable Inputs (Level 3) | Interest rate swaps
Schedule of financial assets and liabilities that were accounted for at fair value on a recurring basis
Derivative liability	0
Nonrecurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Impairment	0
Acquisitions	0
Nonrecurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Impairment	0
Acquisitions	0
Nonrecurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Abstract]
Impairment	198,095,000
Acquisitions	1,691,000
Oil and gas properties, gross	$407,500,000

Derivative_Financial_Instrumen2

Derivative Financial Instruments - Commodity Derivatives (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
Realized and Unrealized Gains (Losses) Related to Derivatives [Roll Forward]
Total gain (loss) on derivatives	$21,019	($15,175)
Derivative cash settlements paid (received)	-40,337	3,610
Not designated as hedging instrument | Commodity contract
Realized and Unrealized Gains (Losses) Related to Derivatives [Roll Forward]
Beginning fair value of interest rate swaps			153,099	17,673
Ending fair value of interest rate swaps	133,242	5,397	153,099	17,673
Not designated as hedging instrument | Commodity contract | Oil
Realized and Unrealized Gains (Losses) Related to Derivatives [Roll Forward]
Total gain (loss) on derivatives	13,594	-12,260
Derivative cash settlements paid (received)	-32,200	2,556
Not designated as hedging instrument | Commodity contract | Natural gas
Realized and Unrealized Gains (Losses) Related to Derivatives [Roll Forward]
Total gain (loss) on derivatives	6,886	-3,626
Derivative cash settlements paid (received)	($8,137)	$1,054

Derivative_Financial_Instrumen3

Derivative Financial Instruments - Offsetting Derivative Assets and Liabilities (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Offsetting Derivative Assets:
Gross Amounts of Recognized Assets	$203,594	$223,778
Gross Amounts Offset in the Consolidated Balance Sheets	-70,352	-70,679
Net Amounts Presented in the Consolidated Balance Sheets	133,242	153,099
Offsetting Derivative Liabilities:
Gross Amounts of Recognized Liabilities	-71,892	-72,759
Gross Amounts Offset in the Consolidated Balance Sheets	70,352	70,679
Net Amounts Presented in the Consolidated Balance Sheets	-1,540	-2,080
Commodity contract
Offsetting Derivative Assets:
Gross Amounts of Recognized Assets	203,594	223,778
Gross Amounts Offset in the Consolidated Balance Sheets	-70,352	-70,679
Net Amounts Presented in the Consolidated Balance Sheets	133,242	153,099
Offsetting Derivative Liabilities:
Gross Amounts of Recognized Liabilities	-70,352	-70,679
Gross Amounts Offset in the Consolidated Balance Sheets	70,352	70,679
Net Amounts Presented in the Consolidated Balance Sheets	0	0
Interest rate contract
Offsetting Derivative Liabilities:
Gross Amounts of Recognized Liabilities	-1,540	-2,080
Gross Amounts Offset in the Consolidated Balance Sheets	0	0
Net Amounts Presented in the Consolidated Balance Sheets	($1,540)	($2,080)

Derivative_Financial_Instrumen4

Derivative Financial Instruments - Schedule of Derivatives, Notional Amounts Outstanding (Details) (USD $)	Mar. 31, 2015	Sep. 30, 2014
In Thousands, unless otherwise specified	bbl	MMBTU
NYMEX WTI Swaps | Crude Oil | April-December 2015
Derivative [Line Items]
Volumes	914,735
Average Price	79.14
NYMEX WTI Swaps | Crude Oil | April-December 2015 | Minimum
Derivative [Line Items]
Price Range	52
NYMEX WTI Swaps | Crude Oil | April-December 2015 | Maximum
Derivative [Line Items]
Price Range	100.2
NYMEX WTI Swaps | Crude Oil | 2016
Derivative [Line Items]
Volumes	228,600
Average Price	87.94
NYMEX WTI Swaps | Crude Oil | 2016 | Minimum
Derivative [Line Items]
Price Range	86.3
NYMEX WTI Swaps | Crude Oil | 2016 | Maximum
Derivative [Line Items]
Price Range	99.85
NYMEX WTI Swaps | Crude Oil | 2017
Derivative [Line Items]
Volumes	182,500
Average Price	84.75
NYMEX WTI Swaps | Crude Oil | 2017 | Minimum
Derivative [Line Items]
Price Range	84.75
Midland-to-Cushing Differential Swaps [Member] | Crude Oil | April-December 2015
Derivative [Line Items]
Volumes	2,475,000
Average Price	-1.77
Midland-to-Cushing Differential Swaps [Member] | Crude Oil | April-December 2015 | Minimum
Derivative [Line Items]
Price Range	-1.65
Midland-to-Cushing Differential Swaps [Member] | Crude Oil | April-December 2015 | Maximum
Derivative [Line Items]
Price Range	-1.9
NYMEX WTI Derivative Three-Way Collar Contracts | Crude Oil | April-December 2015
Derivative [Line Items]
Volumes	997,400
NYMEX WTI Derivative Three-Way Collar Contracts | Crude Oil | April-December 2015 | Put option | Short
Derivative [Line Items]
Average Strike Price	64.87
NYMEX WTI Derivative Three-Way Collar Contracts | Crude Oil | April-December 2015 | Put option | Long
Derivative [Line Items]
Average Strike Price	89.6
NYMEX WTI Derivative Three-Way Collar Contracts | Crude Oil | April-December 2015 | Call option | Short
Derivative [Line Items]
Average Strike Price	111.39
NYMEX WTI Derivative Three-Way Collar Contracts | Crude Oil | 2016
Derivative [Line Items]
Volumes	621,300
NYMEX WTI Derivative Three-Way Collar Contracts | Crude Oil | 2016 | Put option | Short
Derivative [Line Items]
Average Strike Price	63.37
NYMEX WTI Derivative Three-Way Collar Contracts | Crude Oil | 2016 | Put option | Long
Derivative [Line Items]
Average Strike Price	88.37
NYMEX WTI Derivative Three-Way Collar Contracts | Crude Oil | 2016 | Call option | Short
Derivative [Line Items]
Average Strike Price	106.4
NYMEX WTI Derivative Three-Way Collar Contracts | Crude Oil | 2017
Derivative [Line Items]
Volumes	72,400
NYMEX WTI Derivative Three-Way Collar Contracts | Crude Oil | 2017 | Put option | Short
Derivative [Line Items]
Average Strike Price	60
NYMEX WTI Derivative Three-Way Collar Contracts | Crude Oil | 2017 | Put option | Long
Derivative [Line Items]
Average Strike Price	85
NYMEX WTI Derivative Three-Way Collar Contracts | Crude Oil | 2017 | Call option | Short
Derivative [Line Items]
Average Strike Price	104.2
NYMEX WTI Enhanced Swap Contracts 1 | Crude Oil | 2016
Derivative [Line Items]
Volumes	183,000
Average Price	91.7
NYMEX WTI Enhanced Swap Contracts 1 | Crude Oil | 2016 | Put option | Short
Derivative [Line Items]
Average Strike Price	82
NYMEX WTI Enhanced Swap Contracts 1 | Crude Oil | 2016 | Put option | Long
Derivative [Line Items]
Average Strike Price	57
NYMEX WTI Enhanced Swap Contracts 1 | Crude Oil | 2017
Derivative [Line Items]
Volumes	182,500
Average Price	90.85
NYMEX WTI Enhanced Swap Contracts 1 | Crude Oil | 2017 | Put option | Short
Derivative [Line Items]
Average Strike Price	82
NYMEX WTI Enhanced Swap Contracts 1 | Crude Oil | 2017 | Put option | Long
Derivative [Line Items]
Average Strike Price	57
NYMEX WTI Enhanced Swap Contracts 1 | Crude Oil | 2018
Derivative [Line Items]
Volumes	127,750
Average Price	90.5
NYMEX WTI Enhanced Swap Contracts 1 | Crude Oil | 2018 | Put option | Short
Derivative [Line Items]
Average Strike Price	82
NYMEX WTI Enhanced Swap Contracts 1 | Crude Oil | 2018 | Put option | Long
Derivative [Line Items]
Average Strike Price	57
NYMEX WTI Enhanced Swap Contracts 2 | Crude Oil | April-December 2015
Derivative [Line Items]
Volumes	688,000
Average Price	93.79
NYMEX WTI Enhanced Swap Contracts 2 | Crude Oil | April-December 2015 | Put option | Short
Derivative [Line Items]
Average Strike Price	77.01
NYMEX Henry Hub, Waha, ANR-OK and CIG-Rockies Swaps | Natural gas | April-December 2015
Derivative [Line Items]
Volumes	13,963,300
Average Price	4.39
NYMEX Henry Hub, Waha, ANR-OK and CIG-Rockies Swaps | Natural gas | April-December 2015 | Minimum
Derivative [Line Items]
Price Range	3.98
NYMEX Henry Hub, Waha, ANR-OK and CIG-Rockies Swaps | Natural gas | April-December 2015 | Maximum
Derivative [Line Items]
Price Range	5.82
NYMEX Henry Hub, Waha, ANR-OK and CIG-Rockies Swaps | Natural gas | 2016
Derivative [Line Items]
Volumes	1,419,200
Average Price	4.3
NYMEX Henry Hub, Waha, ANR-OK and CIG-Rockies Swaps | Natural gas | 2016 | Minimum
Derivative [Line Items]
Price Range	4.12
NYMEX Henry Hub, Waha, ANR-OK and CIG-Rockies Swaps | Natural gas | 2016 | Maximum
Derivative [Line Items]
Price Range	5.3
NYMEX Henry Hub Derivative Three-Way Collar Contracts | Natural gas | April-December 2015
Derivative [Line Items]
Volumes	6,030,000
NYMEX Henry Hub Derivative Three-Way Collar Contracts | Natural gas | April-December 2015 | Put option | Short
Derivative [Line Items]
Average Strike Price	3.66
NYMEX Henry Hub Derivative Three-Way Collar Contracts | Natural gas | April-December 2015 | Put option | Long
Derivative [Line Items]
Average Strike Price	4.21
NYMEX Henry Hub Derivative Three-Way Collar Contracts | Natural gas | April-December 2015 | Call option | Short
Derivative [Line Items]
Average Strike Price	5.01
NYMEX Henry Hub Derivative Three-Way Collar Contracts | Natural gas | 2016
Derivative [Line Items]
Volumes	5,580,000
NYMEX Henry Hub Derivative Three-Way Collar Contracts | Natural gas | 2016 | Put option | Short
Derivative [Line Items]
Average Strike Price	3.75
NYMEX Henry Hub Derivative Three-Way Collar Contracts | Natural gas | 2016 | Put option | Long
Derivative [Line Items]
Average Strike Price	4.25
NYMEX Henry Hub Derivative Three-Way Collar Contracts | Natural gas | 2016 | Call option | Short
Derivative [Line Items]
Average Strike Price	5.08
NYMEX Henry Hub Derivative Three-Way Collar Contracts | Natural gas | 2017
Derivative [Line Items]
Volumes	5,040,000
NYMEX Henry Hub Derivative Three-Way Collar Contracts | Natural gas | 2017 | Put option | Short
Derivative [Line Items]
Average Strike Price	3.75
NYMEX Henry Hub Derivative Three-Way Collar Contracts | Natural gas | 2017 | Put option | Long
Derivative [Line Items]
Average Strike Price	4.25
NYMEX Henry Hub Derivative Three-Way Collar Contracts | Natural gas | 2017 | Call option | Short
Derivative [Line Items]
Average Strike Price	5.53
Henry Hub NYMEX to Northwest Pipeline Natural Gas Differential Swaps | Natural gas | April-December 2015
Derivative [Line Items]
Volumes		9,000,000
Average Price		-0.13
Henry Hub NYMEX to NGPL Midcon Natural Gas Differential Swaps [Member] | Natural gas | April-December 2015
Derivative [Line Items]
Volumes		360,000
Average Price		-0.15
Interest rate swaps | Libor Swap All Tranches [Member]
Derivative [Line Items]
Estimated Fair Market Value	($1,540)
Interest rate swaps | Libor Swap Tranche 1
Derivative [Line Items]
Notional Amount	29,000
Fixed Rate	3.07%
Estimated Fair Market Value	-459
Interest rate swaps | Libor Swap Tranche 2
Derivative [Line Items]
Notional Amount	13,000
Fixed Rate	3.11%
Estimated Fair Market Value	-235
Interest rate swaps | Libor Swap Tranche 3
Derivative [Line Items]
Notional Amount	12,000
Fixed Rate	3.13%
Estimated Fair Market Value	-215
Interest rate swaps | Libor Swap Tranche 4
Derivative [Line Items]
Notional Amount	50,000
Fixed Rate	2.50%
Estimated Fair Market Value	($631)
Henry Hub NYMEX to California SoCal NGI Natural Gas Differential Swaps [Member] | Natural gas | April-December 2015
Derivative [Line Items]
Volumes		180,000
Average Price		0.19
Henry Hub NYMEX to San Juan Basin Natural Gas Differential Swaps [Member] | Natural gas | April-December 2015
Derivative [Line Items]
Volumes		360,000
Average Price		-0.12
Henry Hub NYMEX to West Texas WAHA Natural Gas Differential Swaps [Member] | Natural gas | April-December 2015
Derivative [Line Items]
Volumes		4,500,000
Average Price		-0.1

Derivative_Financial_Instrumen5

Derivative Financial Instruments - Schedule of Derivatives, Gain (Loss) on Derivative Activity (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Cash settlements paid	($40,337)	$3,610
Interest rate swaps | Not designated as hedging instrument
Derivative Instruments, Gain (Loss) [Line Items]
Beginning fair value of interest rate swaps	-2,080	-4,759
Cash settlements paid	688	886
Ending fair value of interest rate swaps	-1,540	-4,047
Interest rate swaps | Not designated as hedging instrument | Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Total loss on interest rate swaps	($148)	($174)

Asset_Retirement_Obligation_De

Asset Retirement Obligation (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2013
Changes in the ARO
Asset retirement obligation b beginning of period	$226,525
Liabilities incurred with properties acquired	11,725	50,487
Liabilities incurred with properties drilled	0	941
Liabilities settled during the period	-502	-2,918
Liabilities associated with properties sold	-19	-5,891
Current period accretion	2,517	8,120
Asset retirement obligation b end of period	$240,246	$175,786

Partners_Equity_Preferred_Unit

Partners' Equity - Preferred Units (Details) (USD $)	0 Months Ended			3 Months Ended	0 Months Ended
In Millions, except Share data, unless otherwise specified	Jun. 04, 2014	12-May-14	Apr. 17, 2014	Mar. 31, 2015	Jun. 17, 2014	Jul. 01, 2014
Class of Stock [Line Items]
Liquidation preference (in dollars per share)				25
WPX acquisition
Class of Stock [Line Items]
Equity interests issuable (in shares)	300,000
Conversion terms, minimum distribution per share	$0.90
WPX acquisition | Immediate vesting
Class of Stock [Line Items]
Equity interests issuable (in shares)	100,000
WPX acquisition | Ratable vesting
Class of Stock [Line Items]
Equity interests issuable (in shares)	10,000
Additional cash consideration	$35.50
WPX acquisition | Forfeiture, first two anniversaries
Class of Stock [Line Items]
Equity interests forfeiture (in shares)	66,666
WPX acquisition | Forfeiture, third anniversary
Class of Stock [Line Items]
Equity interests forfeiture (in shares)	66,668
Series A Preferred Equity
Class of Stock [Line Items]
Stock issuance (in shares)			2,000,000
Share price			$25
Dividend rate				8.00%
Additional shares of underwriter purchase option		300,000
Series A Preferred Equity | three-month LIBOR
Class of Stock [Line Items]
Variable dividend rate				5.24%
Series B Preferred Equity
Class of Stock [Line Items]
Stock issuance (in shares)					7,000,000
Share price					$25
Series B Preferred Equity | three-month LIBOR
Class of Stock [Line Items]
Variable dividend rate				5.26%
Series B Preferred Equity | Over-Allotment Option
Class of Stock [Line Items]
Stock issuance (in shares)						200,000
Unvested IDUs [Member] | WPX acquisition
Class of Stock [Line Items]
Equity interests issuable (in shares)	200,000

Partners_Equity_Income_loss_pe

Partners' Equity - Income (loss) per unit (Details) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Earnings Per Share [Abstract]
Net loss	($228,854)	$526
Distributions to Preferred unitholders	-4,750	0
Net income (loss) available to unitholders	($233,604)	$526
Weighted average number of units outstanding (in shares)	68,921,000	57,309,000
Effect of dilutive securities:
Restricted and phantom units (in shares)	0	58,000
Weighted average units and potential common units outstanding (in shares)	68,921,000	57,367,000
Basic income (loss) per unit (in dollars per share)	($3.39)	$0.01
Phantom share units (PSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive restricted units excluded from computation of EPS	862,064	289,977
Restricted stock units (RSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive restricted units excluded from computation of EPS	278,383	201,643

UnitBased_Compensation_LTIP_Un

Unit-Based Compensation - LTIP, Unit Appreciation Rights and Unit Options (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual interest rate	1.30%
Unit appreciation rights (UARs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units issued as compensation. gross	13,500
Unit award expiration period	7 years
Share-based compensation expense	5,181	($162,916)
Unrecognized compensation costs	12,321
Unrecognized compensation costs, weighted-average remaining period for recognition	2 years 5 months 5 days
Volatility	42.00%
Share based compensation, forfeiture rate	4.70%
Annual distribution rate per unit (in dollars per share)	2.44
Annual interest rate	1.30%
Unit appreciation rights (UARs) | Ratable vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units issued as compensation. gross	13,500		136,100
Award vesting period	3 years		3 years
Unit appreciation rights (UARs) | Cliff vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units issued as compensation. gross			105,174
Award vesting period			3 years
Restricted stock units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	600,000	500,000
Unrecognized compensation costs	4,300,000
Unrecognized compensation costs, weighted-average remaining period for recognition	2 years 1 month 24 days
Phantom share units (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	400,000	$300,000
Long Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units authorized for issuance (in shares)	2,000,000
Units issued as compensation (in shares)	1,820,306
Long Term Incentive Plan | Unit option awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units issued as compensation (in shares)	266,014
Long Term Incentive Plan | Restricted stock units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units issued as compensation (in shares)	561,850
Long Term Incentive Plan | Phantom share units (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units issued as compensation (in shares)	862,064
Long Term Incentive Plan | Unrestricted units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units issued as compensation (in shares)	130,378

UnitBased_Compensation_Option_

Unit-Based Compensation - Option and UAR Activity (Details) (Unit appreciation rights (UARs), USD $)	3 Months Ended
	Mar. 31, 2015
Unit appreciation rights (UARs)
Units (in shares)
Outstanding	671,229
Granted	13,500
Forfeited	-2,800
Outstanding	681,929
Options and UARs exercisable	244,219
Weighted-Average Exercise Price (in dollars per share)
Outstanding	$26.97
Granted	$11.16
Forfeited	$29.62
Outstanding	$26.65
Options and UARs exercisable	$25.58
Weighted-Average Remaining Contractual Term
Outstanding	4 years 11 months 10 days
Options and UARs exercisable	3 years 5 months 6 days
Aggregate Intrinsic Value
Outstanding	$900
Options and UARs exercisable	$0

UnitBased_Compensation_Status_

Unit-Based Compensation - Status of the Partnership's non-vested UARs (Details) (Unit appreciation rights (UARs), USD $)	3 Months Ended
	Mar. 31, 2015
Unit appreciation rights (UARs)
Number of Units
Non-vested at January 1, 2015	451,173
Granted	13,500
Vested	-24,163
Forfeited	-2,800
Non-vested at March 31, 2015	437,710
Weighted- Average Exercise Price
Non-vested at January 1, 2015	$27.69
Granted	$11.16
Vested	$26.36
Forfeited	$29.62
Non-vested at March 31, 2015	$27.24

UnitBased_Compensation_Weighte

Unit-Based Compensation - Weighted Average Assumptions (Details) (USD $)	3 Months Ended
	Mar. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual interest rate	1.30%
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life (years)	4 years 11 months 10 days
Annual interest rate	1.30%
Annual distribution rate per unit (in dollars per share)	2.44
Volatility	42.00%

UnitBased_Compensation_Phantom

Unit-Based Compensation - Phantom, Board and Restricted Units (Details) (USD $)	3 Months Ended		12 Months Ended	0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Feb. 24, 2015	Mar. 04, 2014	Sep. 21, 2009	Mar. 07, 2013	15-May-14
Non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Value of each unit at issuance (in dollars per share)								27.5
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	13,500
Unvested units not included in consolidated balance sheet (in shares)	437,710		451,173
Share-based compensation expense	$5,181	($162,916)
Unrecognized compensation costs	12,321
Unrecognized compensation costs, period of recognition	2 years 5 months 5 days
Stock Appreciation Rights (SARs) [Member] | Ratable vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years		3 years
Stock Appreciation Rights (SARs) [Member] | Cliff vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			3 years
Subjective phantom share units (PSUs) | Executive officers
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)				341,251	117,197
Subjective phantom share units (PSUs) | Executive officers | Ratable vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period						3 years
Objective phantom share units (PSUs) | Executive officers
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award measurement period							3 years
Granted (in shares)				259,998	102,572
Objective phantom share units (PSUs) | Executive officers | Ratable vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period							3 years
Objective phantom share units (PSUs) | Executive officers | Three-step process vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period						3 years
Objective phantom share units (PSUs) | Executive officers | Three-step process vesting, each of first two steps
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage						50.00%
Objective phantom share units (PSUs) | Executive officers | Cliff vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period							3 years
Phantom share units (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Partnership unit conversion ratio (in shares)	1
Share-based compensation expense	400,000	300,000
Restricted stock units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested units not included in consolidated balance sheet (in shares)	278,383
Share-based compensation expense	600,000	500,000
Unrecognized compensation costs	$4,300,000
Unrecognized compensation costs, period of recognition	2 years 1 month 24 days
Restricted stock units (RSUs) | Non-executive employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	28,000
Restricted stock units (RSUs) | Non-executive employees | Ratable vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Restricted stock units (RSUs) | Non-executive employees and certain executives
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)			127,845
Restricted stock units (RSUs) | Non-executive employees and certain executives | Ratable vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			3 years
Unrestricted units | Non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)								3,628
Individuals eligible for plan								5

Subsidiary_Guarantors_Details

Subsidiary Guarantors (Details) (USD $)	12 Months Ended
	8-May-14	Mar. 31, 2015	Dec. 31, 2014	Mar. 18, 2014	13-May-14	28-May-13
	offering
Debt Instrument [Line Items]
Long-term debt, gross		$987,000,000	$959,000,000
Senior notes
Debt Instrument [Line Items]
Number of private offerings	2
Aggregate principal amount				250,000,000
Percent of subsidiaries owned		100.00%
6.625% Senior Notes due 2021 | Senior notes
Debt Instrument [Line Items]
Long-term debt, gross		$550,000,000	$550,000,000		$300,000,000	$250,000,000

Subsequent_Events_Details

Subsequent Events (Details) (Subsequent event, USD $)	Apr. 16, 2015
Subsequent event
Subsequent Event [Line Items]
Distributions declared and paid (in dollars per share)	$0.35