Western Midstream Partners 10-Q 29 Oct 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Oct. 26, 2015
Document And Entity Information [Abstract]
Trading Symbol	WES
Entity Registrant Name	Western Gas Partners LP
Entity Central Index Key	1,414,475
Document Type	10-Q
Document Period End Date	Sep. 30, 2015
Amendment Flag	false
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Units Outstanding		128,574,646

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands		3 Months Ended			9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014		Sep. 30, 2015		Sep. 30, 2014
Revenues and Other
Total revenues and other		$ 385,101	$ 357,521	[1]	$ 1,190,082		$ 1,016,151	[1]
Equity income, net	[2],[3]	21,976	19,063	[1]	59,137	[4]	41,322	[1],[4]
Operating expenses
Cost of product	[5]	127,721	113,217	[1]	414,378		330,926	[1]
Operation and maintenance	[5]	80,633	67,489	[1]	218,640		184,023	[1]
General and administrative	[5]	9,318	8,339	[1]	28,497		25,688	[1]
Property and other taxes		8,343	6,793	[1]	25,641		21,343	[1]
Depreciation, amortization and impairments		65,688	47,277	[1]	201,941		134,667	[1]
Total operating expenses		291,703	243,115	[1]	889,097		696,647	[1]
Gain on divestiture, net		77,244	0		77,244		0	[1]
Operating income		192,618	133,469	[1]	437,366		360,826	[1]
Interest income - affiliates	[6]	4,225	4,225	[1]	12,675		12,675	[1]
Interest expense	[7]	(31,773)	(20,878)	[1]	(82,337)		(55,703)	[1]
Other income (expense), net		85	97	[1]	227		788	[1]
Income before income taxes		165,155	116,913	[1]	367,931		318,586	[1]
Income tax (benefit) expense		1,661	3,891	[1]	4,305		8,199	[1]
Net income		163,494	113,022	[1]	363,626		310,387	[1]
Net income attributable to noncontrolling interest		2,188	3,863	[1]	8,230		11,005	[1]
Net income attributable to Western Gas Partners, LP		161,306	109,159	[1]	355,396		299,382	[1]
Limited partners' interest in net income:
Pre-acquisition net (income) loss allocated to Anadarko		0	(6,482)	[1]	(1,742)		(13,282)	[1]
General partner interest in net (income) loss	[8]	(50,213)	(31,058)	[1]	(138,121)		(83,939)	[1]
Limited partners' interest in net income	[8]	$ 111,093	$ 71,619	[1]	$ 215,533		$ 202,161	[1]
Net income per common unit - basic	[9]	$ 0.77	$ 0.60	[1]	$ 1.46		$ 1.71	[1]
Net income per common unit - diluted	[9],[10]	$ 0.77	$ 0.60	[1]	$ 1.46		$ 1.71	[1]
Affiliates [Member]
Revenues and Other
Gathering, processing and transportation of natural gas and natural gas liquids		$ 141,556	$ 124,829	[1]	$ 431,182		$ 340,775	[1]
Natural gas, natural gas liquids and drip condensate sales		105,032	142,025	[1]	345,385		424,207	[1]
Other		870	2,778	[1]	1,172		4,349	[1]
Total revenues and other	[3]	247,458	269,632	[1]	777,739		769,331	[1]
Operating expenses
Cost of product	[3]	35,673	27,034		132,663		85,071
Operation and maintenance	[11]	17,662	15,583		50,534		44,961
General and administrative	[12]	7,671	7,016		22,556		21,243
Total operating expenses		61,006	49,633		205,753		151,275
Interest expense	[13]	(4,310)	0		(9,920)		0
Third Parties [Member]
Revenues and Other
Gathering, processing and transportation of natural gas and natural gas liquids		94,082	70,996	[1]	267,566		201,985	[1]
Natural gas, natural gas liquids and drip condensate sales		41,968	11,647	[1]	141,489		37,533	[1]
Other		1,593	5,246	[1]	3,288		7,302	[1]
Total revenues and other		137,643	87,889	[1]	412,343		246,820	[1]
Operating expenses
Interest expense		$ (27,463)	$ (20,878)		$ (72,417)		$ (55,703)
[1]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.
[2]	Income earned from equity investments is classified as affiliate. See Note 1.
[3]	Represents amounts earned or incurred on and subsequent to the date of acquisition of the Partnership assets, as well as amounts earned or incurred by Anadarko on a historical basis related to the Partnership assets prior to the acquisition of such assets, recognized under gathering, treating or processing agreements, and purchase and sale agreements.
[4]	Income earned on, distributions from and contributions to equity investments are classified as affiliate. See Note 1.
[5]	Cost of product includes product purchases from Anadarko (as defined in Note 1) of $35.7 million and $132.7 million for the three and nine months ended September 30, 2015, respectively, and $27.0 million and $85.1 million for the three and nine months ended September 30, 2014, respectively. Operation and maintenance includes charges from Anadarko of $17.7 million and $50.5 million for the three and nine months ended September 30, 2015, respectively, and $15.6 million and $45.0 million for the three and nine months ended September 30, 2014, respectively. General and administrative includes charges from Anadarko of $7.7 million and $22.6 million for the three and nine months ended September 30, 2015, respectively, and $7.0 million and $21.2 million for the three and nine months ended September 30, 2014, respectively. See Note 5.
[6]	Represents interest income recognized on the note receivable from Anadarko.
[7]	Includes affiliate (as defined in Note 1) interest expense of $4.3 million and $9.9 million for the three and nine months ended September 30, 2015, respectively, and zero for each of the three and nine months ended September 30, 2014. See Note 2 and Note 9.
[8]	Represents net income earned on and subsequent to the date of acquisition of the Partnership assets (as defined in Note 1). See Note 4.
[9]	See Note 4 for the calculation of net income per unit.
[10]	Inclusion of Class C units in the calculation would have had an anti-dilutive effect.
[11]	Represents expenses incurred on and subsequent to the date of the acquisition of the Partnership assets, as well as expenses incurred by Anadarko on a historical basis related to the Partnership assets prior to the acquisition of such assets.
[12]	Represents general and administrative expense incurred on and subsequent to the date of the Partnership’s acquisition of the Partnership assets, as well as a management services fee for reimbursement of expenses incurred by Anadarko for periods prior to the acquisition of the Partnership assets by the Partnership. These amounts include equity-based compensation expense allocated to the Partnership by Anadarko (see WES LTIP and WGP LTIP and Anadarko Incentive Plans within this Note 5).
[13]	For the three and nine months ended September 30, 2015, includes accretion expense recognized on the Deferred purchase price obligation - Anadarko for the acquisition of DBJV (see Note 2 and Note 9).

Consolidated Statements of Inc3

Consolidated Statements of Income (Parenthetical) - USD ($) $ in Thousands		3 Months Ended			9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014		Sep. 30, 2015	Sep. 30, 2014
Cost of product	[1]	$ 127,721	$ 113,217	[2]	$ 414,378	$ 330,926	[2]
Operation and maintenance	[1]	80,633	67,489	[2]	218,640	184,023	[2]
General and administrative	[1]	9,318	8,339	[2]	28,497	25,688	[2]
Interest expense	[3]	31,773	20,878	[2]	82,337	55,703	[2]
Affiliates [Member]
Cost of product	[4]	35,673	27,034		132,663	85,071
Operation and maintenance	[5]	17,662	15,583		50,534	44,961
General and administrative	[6]	7,671	7,016		22,556	21,243
Interest expense	[7]	$ 4,310	$ 0		$ 9,920	$ 0
[1]	Cost of product includes product purchases from Anadarko (as defined in Note 1) of $35.7 million and $132.7 million for the three and nine months ended September 30, 2015, respectively, and $27.0 million and $85.1 million for the three and nine months ended September 30, 2014, respectively. Operation and maintenance includes charges from Anadarko of $17.7 million and $50.5 million for the three and nine months ended September 30, 2015, respectively, and $15.6 million and $45.0 million for the three and nine months ended September 30, 2014, respectively. General and administrative includes charges from Anadarko of $7.7 million and $22.6 million for the three and nine months ended September 30, 2015, respectively, and $7.0 million and $21.2 million for the three and nine months ended September 30, 2014, respectively. See Note 5.
[2]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.
[3]	Includes affiliate (as defined in Note 1) interest expense of $4.3 million and $9.9 million for the three and nine months ended September 30, 2015, respectively, and zero for each of the three and nine months ended September 30, 2014. See Note 2 and Note 9.
[4]	Represents amounts earned or incurred on and subsequent to the date of acquisition of the Partnership assets, as well as amounts earned or incurred by Anadarko on a historical basis related to the Partnership assets prior to the acquisition of such assets, recognized under gathering, treating or processing agreements, and purchase and sale agreements.
[5]	Represents expenses incurred on and subsequent to the date of the acquisition of the Partnership assets, as well as expenses incurred by Anadarko on a historical basis related to the Partnership assets prior to the acquisition of such assets.
[6]	Represents general and administrative expense incurred on and subsequent to the date of the Partnership’s acquisition of the Partnership assets, as well as a management services fee for reimbursement of expenses incurred by Anadarko for periods prior to the acquisition of the Partnership assets by the Partnership. These amounts include equity-based compensation expense allocated to the Partnership by Anadarko (see WES LTIP and WGP LTIP and Anadarko Incentive Plans within this Note 5).
[7]	For the three and nine months ended September 30, 2015, includes accretion expense recognized on the Deferred purchase price obligation - Anadarko for the acquisition of DBJV (see Note 2 and Note 9).

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands		Sep. 30, 2015	Dec. 31, 2014	[1]
Current assets
Cash and cash equivalents		$ 73,200	$ 67,054
Accounts receivable, net	[2]	150,538	109,243
Other current assets	[3]	11,399	10,067
Total current assets		235,137	186,364
Note receivable - Anadarko		260,000	260,000
Property, plant and equipment
Cost		5,862,721	5,626,650
Less accumulated depreciation		1,072,799	1,055,207
Net property, plant and equipment		4,789,922	4,571,443
Goodwill		387,633	389,087
Other intangible assets		839,234	884,857
Equity investments		629,627	634,492
Other assets		30,779	28,289
Total assets		7,172,332	6,954,532
Current liabilities
Accounts and natural gas imbalance payables	[4]	57,598	54,232
Accrued ad valorem taxes		26,416	14,812
Accrued liabilities		138,812	170,789
Total current liabilities		222,826	239,833
Long-term debt		2,587,189	2,422,954
Deferred income taxes		7,037	45,656
Asset retirement obligations and other		119,422	111,714
Deferred purchase price obligation - Anadarko	[5]	184,196	0
Total long-term liabilities		2,897,844	2,580,324
Total liabilities		3,120,670	2,820,157
Equity and partners' capital
General partner units (2,583,068 units issued and outstanding at September 30, 2015, and December 31, 2014)		123,792	105,725
Net investment by Anadarko		0	122,509
Total partners' capital		3,984,112	4,064,905
Noncontrolling interest		67,550	69,470
Total equity and partners' capital		4,051,662	4,134,375
Total liabilities, equity and partners' capital		7,172,332	6,954,532
Common Units [Member]
Equity and partners' capital
Common units (128,574,646 and 127,695,130 units issued and outstanding at September 30, 2015, and December 31, 2014, respectively) and Class C Units (11,230,814 and 10,913,853 units issued and outstanding at September 30, 2015, and December 31, 2014, respectively)		3,115,480	3,119,714
Class C Units [Member]
Equity and partners' capital
Common units (128,574,646 and 127,695,130 units issued and outstanding at September 30, 2015, and December 31, 2014, respectively) and Class C Units (11,230,814 and 10,913,853 units issued and outstanding at September 30, 2015, and December 31, 2014, respectively)		$ 744,840	$ 716,957
[1]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.
[2]	Accounts receivable, net includes amounts receivable from affiliates (as defined in Note 1) of $46.9 million and $64.7 million as of September 30, 2015, and December 31, 2014, respectively.
[3]	Other current assets includes natural gas imbalance receivables from affiliates of zero and $0.2 million as of September 30, 2015, and December 31, 2014, respectively.
[4]	Accounts and natural gas imbalance payables includes amounts payable to affiliates of zero and $0.1 million as of September 30, 2015, and December 31, 2014, respectively.
[5]	See Note 2.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands		Sep. 30, 2015	Dec. 31, 2014
General partner units issued		2,583,068	2,583,068
General partner units outstanding		2,583,068	2,583,068
Accounts receivable, net	[1]	$ 150,538	$ 109,243	[2]
Other current assets	[3]	11,399	10,067	[2]
Accounts and natural gas imbalance payables	[4]	$ 57,598	$ 54,232	[2]
Common Units [Member]
Units issued		128,574,646	127,695,130
Units outstanding		128,574,646	127,695,130
Class C Units [Member]
Units issued		11,230,814	10,913,853
Units outstanding		11,230,814	10,913,853
Affiliates [Member]
Accounts receivable, net		$ 46,900	$ 64,700
Other current assets		0	200
Accounts and natural gas imbalance payables		$ 0	$ 100
[1]	Accounts receivable, net includes amounts receivable from affiliates (as defined in Note 1) of $46.9 million and $64.7 million as of September 30, 2015, and December 31, 2014, respectively.
[2]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.
[3]	Other current assets includes natural gas imbalance receivables from affiliates of zero and $0.2 million as of September 30, 2015, and December 31, 2014, respectively.
[4]	Accounts and natural gas imbalance payables includes amounts payable to affiliates of zero and $0.1 million as of September 30, 2015, and December 31, 2014, respectively.

Consolidated Statement of Equit

Consolidated Statement of Equity and Partners' Capital - 9 months ended Sep. 30, 2015 - USD ($) $ in Thousands		Total	Net Investment by Anadarko [Member]	Common Units [Member]	Class C Units [Member]	General Partner Units [Member]	Noncontrolling Interest [Member]
Balance at Dec. 31, 2014	[1]	$ 4,134,375	$ 122,509	$ 3,119,714	$ 716,957	$ 105,725	$ 69,470
Net income (loss)		363,626	1,742	196,897	18,636	138,121	8,230
Above-market component of swap extensions with Anadarko	[2]	7,916		7,916
Issuance of common units, net of offering expenses		57,353		57,353
Amortization of beneficial conversion feature of Class C units		0		(9,247)	9,247
Distributions to noncontrolling interest owner		(10,150)					(10,150)
Distributions to unitholders		(398,983)		(278,956)		(120,027)
Acquisitions from affiliates		(174,276)	(197,562)	23,286
Contributions of equity-based compensation from Anadarko		2,679		2,625		54
Net pre-acquisition contributions from (distributions to) Anadarko		31,467	31,467
Net distributions to Anadarko of other assets		(4,386)		(4,305)		(81)
Elimination of net deferred tax liabilities		41,844	41,844
Other		197		197
Balance at Sep. 30, 2015		$ 4,051,662	$ 0	$ 3,115,480	$ 744,840	$ 123,792	$ 67,550
[1]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.
[2]	See Note 5.

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2015		Sep. 30, 2014
Cash flows from operating activities
Net income		$ 363,626		$ 310,387	[1]
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and impairments		201,941		134,667	[1]
Non-cash equity-based compensation expense		3,257		3,210	[1]
Deferred income taxes		2,993		4,024	[1]
Accretion and amortization of long-term obligations, net		12,296		2,045	[1]
Equity income, net	[2],[3],[4]	(59,137)		(41,322)	[1]
Distributions from equity investment earnings	[3]	60,645		43,061	[1]
Gain on divestiture, net		(77,244)		0	[1]
Changes in assets and liabilities:
(Increase) decrease in accounts receivable, net		(24,104)		(52,659)	[1]
Increase (decrease) in accounts and natural gas imbalance payables and accrued liabilities, net		15,952		35,807	[1]
Change in other items, net		(1,817)		1,645	[1]
Net cash provided by operating activities		498,408		440,865	[1]
Cash flows from investing activities
Capital expenditures		(473,394)		(529,197)	[1]
Investments in equity affiliates		(9,052)		(63,267)	[1]
Distributions from equity investments in excess of cumulative earnings	[3]	12,409	[5]	14,387	[1]
Net cash used in investing activities		(337,989)		(950,282)	[1]
Cash flows from financing activities
Borrowings, net of debt issuance costs		769,606		1,136,878	[1]
Repayments of debt		(610,000)		(480,000)	[1]
Increase (decrease) in outstanding checks		(1,482)		2,908	[1]
Proceeds from the issuance of common and general partner units, net of offering expenses		57,353		101,502	[1]
Distributions to unitholders		(398,983)		(297,013)	[1]
Distributions to noncontrolling interest owner		(10,150)		(11,349)	[1]
Net contributions from Anadarko		31,467		23,600	[1]
Above-market component of swap extensions with Anadarko	[6]	7,916		0	[1]
Net cash provided by (used in) financing activities		(154,273)		476,526	[1]
Net increase (decrease) in cash and cash equivalents		6,146		(32,891)	[1]
Cash and cash equivalents at beginning of period		67,054	[7]	100,728	[1]
Cash and cash equivalents at end of period		73,200		67,837	[1]
Supplemental disclosures
Net distributions to (contributions from) Anadarko of other assets		4,386		6,398	[1]
Interest paid, net of capitalized interest		60,612		43,504	[1]
Taxes paid (reimbursements received)		(138)		(340)	[1]
Capital lease asset transfer	[8]	0		4,833	[1]
Delaware Basin JV Gathering LLC [Member]
Cash flows from operating activities
Net income				14,238
Adjustments to reconcile net income to net cash provided by operating activities:
Equity income, net				0
Supplemental disclosures
Acquisition of DBJV from Anadarko	[9]	174,276		0	[1]
Affiliates [Member]
Cash flows from investing activities
Contributions in aid of construction costs from affiliates		0		183	[1]
Acquisitions		(12,131)		(372,393)	[1]
Proceeds from the sale of assets		700		0	[1]
Cash flows from financing activities
Distributions to unitholders	[10]	(228,893)		(169,001)
Third Parties [Member]
Cash flows from investing activities
Acquisitions		(3,514)		0	[1]
Proceeds from the sale of assets		$ 146,993		$ 5	[1]
[1]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.
[2]	Income earned from equity investments is classified as affiliate. See Note 1.
[3]	Income earned on, distributions from and contributions to equity investments are classified as affiliate. See Note 1.
[4]	Represents amounts earned or incurred on and subsequent to the date of acquisition of the Partnership assets, as well as amounts earned or incurred by Anadarko on a historical basis related to the Partnership assets prior to the acquisition of such assets, recognized under gathering, treating or processing agreements, and purchase and sale agreements.
[5]	Distributions in excess of cumulative earnings, classified as investing cash flows in the consolidated statements of cash flows, is calculated on an individual investment basis.
[6]	See Note 5.
[7]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.
[8]	For the nine months ended September 30, 2014, represents transfers of $4.6 million from other long-term assets associated with the capital lease component of a processing agreement.
[9]	See Note 2.
[10]	Represents distributions paid under the partnership agreement (see Note 3 and Note 4).

Consolidated Statements of Cas8

Consolidated Statements of Cash Flows (Parenthetical) $ in Thousands	Sep. 30, 2014USD ($)
Natural Gas Processing Plant [Member]
Property, plant and equipment	$ 4,600

Description of Business and Bas

Description of Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Description of Business and Basis of Presentation	1. DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION General. Western Gas Partners, LP is a growth-oriented Delaware master limited partnership formed by Anadarko Petroleum Corporation in 2007 to acquire, own, develop and operate midstream energy assets. For purposes of these consolidated financial statements, the “Partnership” refers to Western Gas Partners, LP and its subsidiaries. The Partnership’s general partner, Western Gas Holdings, LLC (the “general partner” or “GP”), is owned by Western Gas Equity Partners, LP (“WGP”), a Delaware master limited partnership formed by Anadarko Petroleum Corporation in September 2012 to own the Partnership’s general partner, as well as a significant limited partner interest in the Partnership (see Western Gas Equity Partners, LP below). Western Gas Equity Holdings, LLC is WGP’s general partner and is a wholly owned subsidiary of Anadarko Petroleum Corporation. “Anadarko” refers to Anadarko Petroleum Corporation and its subsidiaries, excluding the Partnership and the general partner, and “affiliates” refers to subsidiaries of Anadarko, excluding the Partnership, and includes equity interests in Fort Union Gas Gathering, LLC (“Fort Union”), White Cliffs Pipeline, LLC (“White Cliffs”), Rendezvous Gas Services, LLC (“Rendezvous”), Enterprise EF78 LLC (the “Mont Belvieu JV”), Texas Express Pipeline LLC (“TEP”), Texas Express Gathering LLC (“TEG”) and Front Range Pipeline LLC (“FRP”). The interests in TEP, TEG and FRP are referred to collectively as the “TEFR Interests.” “Equity investment throughput” refers to the Partnership’s 14.81% share of average Fort Union throughput and 22% share of average Rendezvous throughput, but excludes throughput measured in barrels, consisting of the Partnership’s 10% share of average White Cliffs throughput, 25% share of average Mont Belvieu JV throughput, 20% share of average TEP and TEG throughput and 33.33% share of average FRP throughput. The “DJ Basin complex” refers to the Platte Valley system, Wattenberg system and Lancaster plant, all of which were combined into a single complex in the first quarter of 2014. The “MGR assets” include the Red Desert complex, the Granger straddle plant and the 22% interest in Rendezvous. The Partnership is engaged in the business of gathering, processing, compressing, treating and transporting natural gas, condensate, NGLs and crude oil for Anadarko, as well as for third-party producers and customers. As of September 30, 2015 , the Partnership’s assets and investments accounted for under the equity method consisted of the following: Owned and Operated Operated Interests Non-Operated Interests Equity Interests Natural gas gathering systems 12 2 5 2 Natural gas treating facilities 9 4 — 1 Natural gas processing facilities 14 5 — 2 NGL pipelines 3 — — 3 Natural gas pipelines 4 — — — Oil pipelines 1 — — 1 These assets and investments are located in the Rocky Mountains (Colorado, Utah and Wyoming), the Mid-Continent (Kansas and Oklahoma), North-central Pennsylvania and Texas. In June 2015, the Partnership completed the construction and commenced operations of Lancaster Train II, a processing plant located in the DJ Basin complex. In addition, the Partnership is constructing Trains IV, V and VI, all processing plants, at the DBM complex (see Note 2 ), with operations expected to commence during the first half (Train IV) and second half (Train V) of 2016, and mid-2017 (Train VI). 1. DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (CONTINUED) Western Gas Equity Partners, LP. WGP owns the following types of interests in the Partnership: (i) the general partner interest and all of the incentive distribution rights (“IDRs”) in the Partnership, both owned through WGP’s 100% ownership of the Partnership’s general partner and (ii) a significant limited partner interest (see Holdings of Partnership equity in Note 4 ). WGP has no independent operations or material assets other than owning such partnership interests. Basis of presentation. The consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”). The consolidated financial statements include the accounts of the Partnership and entities in which it holds a controlling financial interest. All significant intercompany transactions have been eliminated. Investments in non-controlled entities over which the Partnership exercises significant influence are accounted for under the equity method. The Partnership proportionately consolidates its 33.75% share of the assets, liabilities, revenues and expenses attributable to the Non-Operated Marcellus Interest systems and Anadarko-Operated Marcellus Interest systems and its 50% share of the assets, liabilities, revenues and expenses attributable to the Newcastle system and the DBJV system (see Note 2 ) in the accompanying consolidated financial statements. The 25% membership interest in Chipeta Processing LLC (“Chipeta”) held by a third-party member is reflected within noncontrolling interest in the consolidated financial statements for all periods presented. In preparing financial statements in accordance with GAAP, management makes informed judgments and estimates that affect the reported amounts of assets, liabilities, revenues and expenses. Management evaluates its estimates and related assumptions regularly, using historical experience and other methods considered reasonable. Changes in facts and circumstances or additional information may result in revised estimates and actual results may differ from these estimates. Effects on the business, financial condition and results of operations resulting from revisions to estimates are recognized when the facts that give rise to the revisions become known. The information furnished herein reflects all normal recurring adjustments which are, in the opinion of management, necessary for a fair presentation of the consolidated financial statements, and certain prior-period amounts have been reclassified to conform to the current-year presentation. The Partnership’s unaudited consolidated statements of income reflect the reclassifications of the following amounts, which previously reduced Operation and maintenance expense, to revenues related to Gathering, processing and transportation of natural gas and natural gas liquids: (i) $25.0 million for the nine months ended September 30, 2015 (all of which relates to the six months ended June 30, 2015) and (ii) $12.0 million and $28.6 million for the three and nine months ended September 30, 2014 , respectively. Management determined that the third-party producer reimbursements received for electricity purchased by the Partnership is more appropriately classified as revenues, instead of a reduction to Operation and maintenance expense. This correction of an error has no impact to Net income, cash flows, or any non-GAAP metric the Partnership uses to evaluate its operations (see Key Performance Metrics under Item 2 of this Form 10-Q) and is not considered material to the Partnership’s results of operations for the three and nine months ended September 30, 2015 and 2014 . The Partnership will revise its previously reported 2013, 2014 and 2015 consolidated financial statements, and unaudited interim periods therein as applicable, to reflect the reclassification in future filings. Certain information and note disclosures commonly included in annual financial statements have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Accordingly, the accompanying consolidated financial statements and notes should be read in conjunction with the Partnership’s 2014 Form 10-K, as filed with the SEC on February 26, 2015. Management believes that the disclosures made are adequate to make the information not misleading. Presentation of Partnership assets. The term “Partnership assets” refers to the assets owned and interests accounted for under the equity method (see Note 7 ) by the Partnership as of September 30, 2015 . Because Anadarko controls the Partnership through its ownership and control of WGP, which owns the Partnership’s entire general partner interest, each acquisition of Partnership assets from Anadarko has been considered a transfer of net assets between entities under common control. As such, the Partnership assets acquired from Anadarko were initially recorded at Anadarko’s historic carrying value, which did not correlate to the total acquisition price paid by the Partnership. Further, after an acquisition of Partnership assets from Anadarko, the Partnership may be required to recast its financial statements to include the activities of such Partnership assets from the date of common control. See Note 2 . 1. DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (CONTINUED) For those periods requiring recast, the consolidated financial statements for periods prior to the Partnership’s acquisition of the Partnership assets from Anadarko have been prepared from Anadarko’s historical cost-basis accounts and may not necessarily be indicative of the actual results of operations that would have occurred if the Partnership had owned the Partnership assets during the periods reported. Net income attributable to the Partnership assets acquired from Anadarko for periods prior to the Partnership’s acquisition of the Partnership assets is not allocated to the limited partners. Recently issued accounting standards . The Financial Accounting Standards Board recently issued the following Accounting Standards Updates (“ASUs”): ASU 2015-06, Earnings Per Share (Topic - 260)—Effects on Historical Earnings per Unit of Master Limited Partnership Dropdown Transactions . This ASU contains guidance that addresses the historical earnings per unit presentation for master limited partnerships that apply the two-class method of calculating earnings per unit. When a general partner transfers or “drops down” net assets to a master limited partnership the transaction is accounted for as a transaction between entities under common control and the statements of operations are adjusted retrospectively to reflect the transaction. This ASU specifies that the historical earnings (losses) of a transferred business before the date of a dropdown transaction should be allocated entirely to the general partner, and the previously reported earnings per unit of the limited partners should not change as a result of the dropdown transaction. The ASU also requires additional disclosures about how the rights to the earnings (losses) differ before and after the dropdown transaction occurs for purposes of computing earnings per unit under the two-class method. This ASU is effective for annual and interim periods beginning in 2016 and is required to be adopted using a retrospective approach, with early adoption permitted. While the Partnership believes it is currently in compliance with this ASU, it continues to evaluate the impact of the adoption of this ASU on its consolidated financial statements. ASU 2015-03, Interest—Imputation of Interest (Subtopic 835-30)—Simplifying the Presentation of Debt Issuance Costs and ASU 2015-15, Interest—Imputation of Interest (Subtopic 835-30)—Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements . These ASUs will simplify the presentation of debt issuance costs by requiring such costs, except for those related to revolving credit facilities, to be presented in the balance sheet as a direct deduction from the carrying amount of the related debt liability, rather than as an asset. These ASUs are effective for annual and interim periods beginning in 2016 and are required to be adopted using a retrospective approach, with early adoption permitted. The Partnership does not expect the adoption to have a material impact on its consolidated financial statements. ASU 2015-02, Consolidation—Amendments to the Consolidation Analysis . This ASU will simplify existing requirements by reducing the number of acceptable consolidation models and placing more emphasis on risk of loss when determining a controlling financial interest. The provisions will affect how limited partnerships and similar entities are assessed for consolidation, including the elimination of the presumption that a general partner should consolidate a limited partnership. This ASU is effective for annual and interim periods beginning in 2016 and is required to be adopted using a retrospective or modified retrospective approach, with early adoption permitted. The Partnership is evaluating the impact of the adoption of this ASU on its consolidated financial statements. ASU 2014-09, Revenue from Contracts with Customers . This ASU supersedes the revenue recognition requirements in Topic 605, Revenue Recognition , and industry-specific guidance in Subtopic 932-605, Extractive Activities—Oil and Gas—Revenue Recognition , and requires an entity to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration the entity expects to be entitled to in exchange for those goods or services. The effective date for ASU 2014-09 was delayed through the issuance of ASU 2015-14, Revenue from Contracts with Customers—Deferral of the Effective Date, to annual and interim periods beginning in 2018 and is required to be adopted using one of two retrospective application methods, with early adoption permitted in 2017. The Partnership is evaluating the impact of the adoption of this ASU on its consolidated financial statements.

Acquisitions and Divestitures

Acquisitions and Divestitures	9 Months Ended
	Sep. 30, 2015
Property, Plant and Equipment [Abstract]
Acquisitions and Divestitures	2. ACQUISITIONS AND DIVESTITURES The following table presents the acquisitions completed by the Partnership during 2015 and 2014 , and identifies the funding sources for such acquisitions: thousands except unit and percent amounts Acquisition Date Percentage Deferred Purchase Price Obligation - Anadarko Borrowings Cash On Hand Common Units Issued to Anadarko Class C Units Issued to Anadarko TEFR Interests (1) 03/03/2014 Various (1) $ — $ 350,000 $ 6,250 308,490 — DBM (2) 11/25/2014 100 % — 475,000 298,327 — 10,913,853 DBJV system (3) 03/02/2015 50 % 174,276 — — — — (1) The Partnership acquired a 20% interest in each of TEG and TEP and a 33.33% interest in FRP from Anadarko. These assets gather and transport NGLs primarily from the Anadarko and Denver-Julesburg (“DJ”) Basins. The interests in these entities are accounted for under the equity method of accounting. In connection with the issuance of the common units, the Partnership issued 6,296 general partner units to the general partner in exchange for the general partner’s proportionate capital contribution of $0.4 million . (2) The Partnership acquired Nuevo Midstream, LLC (“Nuevo”) from a third party. Following the acquisition, the Partnership changed the name of Nuevo to Delaware Basin Midstream, LLC (“DBM”). The assets acquired include cryogenic processing plants, a gas gathering system, and related facilities and equipment, which are collectively referred to as the “DBM complex” and serve production from Reeves, Loving and Culberson Counties, Texas and Eddy and Lea Counties, New Mexico. See DBM acquisition below for further information, including the preliminary allocation of the purchase price. (3) The Partnership acquired Anadarko’s interest in Delaware Basin JV Gathering LLC (“DBJV”), which owns a 50% interest in a gathering system and related facilities (the “DBJV system”). The DBJV system is located in the Delaware Basin in Loving, Ward, Winkler and Reeves Counties, Texas. The Partnership will make a cash payment on March 31, 2020, to Anadarko as consideration for the acquisition of DBJV. The Partnership currently estimates the future payment will be $282.8 million , the net present value of which was $174.3 million as of the acquisition date. See DBJV acquisition—Deferred purchase price obligation - Anadarko below. DBJV acquisition . Because the acquisition of DBJV was a transfer of net assets between entities under common control, the Partnership’s historical financial statements previously filed with the SEC have been recast in this Form 10-Q to include the results attributable to the DBJV system as if the Partnership owned DBJV for all periods presented. The consolidated financial statements for periods prior to the Partnership’s acquisition of DBJV have been prepared from Anadarko’s historical cost-basis accounts and may not necessarily be indicative of the actual results of operations that would have occurred if the Partnership had owned DBJV during the periods reported. The following table presents the impact of the DBJV system on revenues and other, equity income, net and net income as presented in the Partnership’s historical consolidated statements of income: Three Months Ended September 30, 2014 thousands Partnership Historical (1) DBJV System Combined Revenues and other $ 341,282 $ 16,239 $ 357,521 Equity income, net 19,063 — 19,063 Net income 106,540 6,482 113,022 Nine Months Ended September 30, 2014 thousands Partnership Historical (1) DBJV System Combined Revenues and other $ 970,027 $ 46,124 $ 1,016,151 Equity income, net 41,322 — 41,322 Net income 296,149 14,238 310,387 (1) As adjusted for the reclassification described in Note 1 . 2. ACQUISITIONS AND DIVESTITURES (CONTINUED) Deferred purchase price obligation - Anadarko. The consideration to be paid by the Partnership for the acquisition of DBJV consists of a cash payment to Anadarko due on March 31, 2020. The cash payment will be equal to (a) eight multiplied by the average of the Partnership’s share in the Net Earnings (see definition below) of the DBJV system for the calendar years 2018 and 2019, less (b) the Partnership’s share of all capital expenditures incurred for the DBJV system between March 1, 2015, and February 29, 2020. Net Earnings is defined as all revenues less cost of product, operating expenses and property taxes, in each case attributable to the DBJV system on an accrual basis. As of the acquisition date, the estimated future payment obligation was $282.8 million , which had a net present value of $174.3 million , using a discount rate of 10% . As of September 30, 2015 , the net present value of this obligation was $184.2 million and has been recorded on the consolidated balance sheet under Deferred purchase price obligation - Anadarko. Accretion expense for the three and nine months ended September 30, 2015 , was $4.3 million and $9.9 million , respectively, and has been recorded as a charge to interest expense. The fair value measurement was calculated using Level 3 inputs, which consisted of management’s estimate of the Partnership’s share of forecasted Net Earnings and capital expenditures for the DBJV system. DBM acquisition . The DBM acquisition has been accounted for under the acquisition method of accounting. The assets acquired and liabilities assumed in the DBM acquisition were recorded in the consolidated balance sheet at their estimated fair values as of the acquisition date. Results of operations attributable to the DBM acquisition were included in the Partnership’s consolidated statement of income beginning on the acquisition date in the fourth quarter of 2014. The following is the preliminary allocation of the purchase price as of September 30, 2015 , including $3.5 million of post-closing purchase price adjustments, to the assets acquired and liabilities assumed in the DBM acquisition as of the acquisition date, pending final review of certain support related to the acquired entity’s assets and liabilities: thousands Current assets $ 62,940 Property, plant and equipment 467,171 Goodwill 282,697 Other intangible assets 811,048 Accounts payables (18,621 ) Accrued liabilities (37,360 ) Deferred income taxes (1,342 ) Asset retirement obligations and other (9,060 ) Total purchase price $ 1,557,473 The purchase price allocation is based on an assessment of the fair value of the assets acquired and liabilities assumed in the DBM acquisition using inputs that are not observable in the market and thus represent Level 3 inputs. The fair values of the processing plants, gathering system, and related facilities and equipment are based on market and cost approaches. The fair value of the intangible assets was determined using an income approach. Deferred taxes represent the tax effects of differences in the tax basis and acquisition-date fair value of the assets acquired and liabilities assumed. Gain on divestiture - Dew and Pinnacle systems. During the third quarter of 2015, the Dew and Pinnacle systems in East Texas were sold to a third party for net proceeds of $146.7 million , after closing adjustments, resulting in a net gain on sale of $77.2 million recorded as Gain on divestiture, net in the Partnership’s consolidated statements of income.

Partnership Distributions

Partnership Distributions	9 Months Ended
	Sep. 30, 2015
Distributions Made to Members or Limited Partners [Abstract]
Partnership Distributions	3. PARTNERSHIP DISTRIBUTIONS The partnership agreement of Western Gas Partners, LP requires the Partnership to distribute all of its available cash (as defined in the partnership agreement) to unitholders of record on the applicable record date within 45 days of the end of each quarter. The Board of Directors of the general partner declared the following cash distributions to the Partnership’s common and general partner unitholders for the periods presented: thousands except per-unit amounts Quarters Ended Total Quarterly Distribution per Unit Total Quarterly Cash Distribution Date of Distribution 2014 March 31 $ 0.625 $ 98,749 May 2014 June 30 0.650 105,655 August 2014 September 30 0.675 111,608 November 2014 December 31 0.700 126,044 February 2015 2015 March 31 $ 0.725 $ 133,203 May 2015 June 30 0.750 139,736 August 2015 September 30 (1) 0.775 146,160 November 2015 (1) On October 14, 2015 , the Board of Directors of the Partnership’s general partner declared a cash distribution to the Partnership’s unitholders of $0.775 per unit, or $146.2 million in aggregate, including incentive distributions, but excluding distributions on Class C units (see Class C unit distributions below). The cash distribution is payable on November 12, 2015 , to unitholders of record at the close of business on November 2, 2015 . Class C unit distributions. The Class C units receive quarterly distributions at a rate equivalent to the Partnership’s common units. The distributions are paid in the form of additional Class C units (“PIK Class C units”) until the scheduled conversion date on December 31, 2017 (unless earlier converted), and the Class C units are disregarded with respect to distributions of the Partnership’s available cash until they are converted to common units. The number of additional PIK Class C units to be issued in connection with a distribution payable on the Class C units is determined by dividing the corresponding distribution attributable to the Class C units by the volume-weighted-average price of the Partnership’s common units for the ten days immediately preceding the payment date for the common unit distribution, less a 6% discount. The Partnership records the PIK Class C unit distributions at fair value at the time of issuance. This Level 2 fair value measurement uses the Partnership’s unit price as a significant input in the determination of the fair value. The Partnership issued the following PIK Class C units to APC Midstream Holdings, LLC (“AMH”), the holder of the Class C units, for the periods presented: thousands except unit amounts For the Quarters Ended PIK Class C Units Implied Fair Value Date of 2014 December 31 (1) 45,711 $ 3,072 February 2015 2015 March 31 118,230 $ 8,101 May 2015 June 30 153,020 8,721 August 2015 (1) Prorated for the 37 -day period the Class C units were outstanding during the fourth quarter of 2014.

Equity and Partners' Capital

Equity and Partners' Capital	9 Months Ended
	Sep. 30, 2015
Partners' Capital Notes [Abstract]
Equity and Partners' Capital	4. EQUITY AND PARTNERS’ CAPITAL Equity offerings. The Partnership completed the following public offerings of its common units during 2015 and 2014, including through its Continuous Offering Programs (“COP”): thousands except unit and per-unit amounts Common Units Issued GP Units Issued (1) Price Per Unit Underwriting Discount and Other Offering Expenses Net Proceeds 2014 $125.0 million COP (2) 1,133,384 23,132 $ 73.48 $ 1,738 $ 83,245 November 2014 equity offering (3) 8,620,153 153,061 70.85 18,615 602,967 2015 $500.0 million COP (4) 873,525 — $ 66.61 $ 805 $ 57,385 (1) Represents general partner units issued to the general partner in exchange for the general partner’s proportionate capital contribution. (2) Represents common and general partner units issued during the year ended December 31, 2014, pursuant to the Partnership’s registration statement filed with the SEC in August 2012 authorizing the issuance of up to an aggregate of $125.0 million of common units (the “$125.0 million COP”). Gross proceeds generated (including the general partner’s proportionate capital contributions) during the year ended December 31, 2014, were $85.0 million . The price per unit in the table above represents an average price for all issuances under the $125.0 million COP during the year ended December 31, 2014. As of December 31, 2014, the Partnership had used all the capacity to issue common units under this registration statement. (3) Includes the issuance of 1,120,153 common units pursuant to the partial exercise of the underwriters’ over-allotment option, the net proceeds from which were $77.0 million . Beginning with this partial exercise, the Partnership’s general partner elected not to make a corresponding capital contribution to maintain its 2.0% interest in the Partnership. (4) Represents common units issued during the nine months ended September 30, 2015 , pursuant to the Partnership’s registration statement filed with the SEC in August 2014 authorizing the issuance of up to an aggregate of $500.0 million of common units (the “$500.0 million COP”). Gross proceeds generated during the three and nine months ended September 30, 2015 , were zero and $58.2 million , respectively. Commissions paid during the three and nine months ended September 30, 2015 , were zero and $0.6 million , respectively. The price per unit in the table above represents an average price for all issuances under the $500.0 million COP during the nine months ended September 30, 2015 . Class C units. In connection with the closing of the DBM acquisition in November 2014, the Partnership issued 10,913,853 Class C units to AMH at a price of $68.72 per unit, generating proceeds of $750.0 million , pursuant to the Unit Purchase Agreement (“UPA”) with Anadarko and AMH. All outstanding Class C units will convert into common units on a one-for-one basis on December 31, 2017, unless the Partnership elects to convert such units earlier or Anadarko extends the conversion date. The Class C units were issued to partially fund the acquisition of DBM, and the UPA contains an optional redemption feature that provides the Partnership the ability to redeem up to $150.0 million of the Class C units within 10 days of the receipt of cash proceeds from an entity that is not an affiliate of the Partnership or AMH, if these cash proceeds were in relation to (i) the assets of DBM, (ii) the equity interests in DBM or (iii) the equity interests in a subsidiary of the Partnership that owns a majority of the outstanding equity interests in DBM. As of September 30, 2015 , no such proceeds had been received and no Class C units had been redeemed. The Class C units were issued at a discount to the then-current market price of the common units into which they are convertible. This discount, totaling $34.8 million , represents a beneficial conversion feature and at December 31, 2014, was reflected as an increase in common unitholders’ capital and a decrease in Class C unitholder capital to reflect the fair value of the Class C units at issuance. The beneficial conversion feature is considered a non-cash distribution that will be recognized from the date of issuance through the date of conversion, resulting in an increase in Class C unitholder capital and a decrease in common unitholders’ capital. The Partnership is amortizing the beneficial conversion feature assuming a conversion date of December 31, 2017, using the effective yield method. The impact of the beneficial conversion feature is also included in the calculation of earnings per unit. 4. EQUITY AND PARTNERS’ CAPITAL (CONTINUED) Common, Class C and general partner units . The Partnership’s common units are listed on the New York Stock Exchange under the symbol “WES.” The following table summarizes the common, Class C and general partner units issued during the nine months ended September 30, 2015 : Common Units Class C Units General Partner Units Total Balance at December 31, 2014 127,695,130 10,913,853 2,583,068 141,192,051 PIK Class C units — 316,961 — 316,961 Long-Term Incentive Plan award vestings 5,991 — — 5,991 $500.0 million COP 873,525 — — 873,525 Balance at September 30, 2015 128,574,646 11,230,814 2,583,068 142,388,528 Holdings of Partnership equity. As of September 30, 2015 , WGP held 49,296,205 common units, representing a 34.6% limited partner interest in the Partnership, and, through its ownership of the general partner, WGP indirectly held 2,583,068 general partner units, representing a 1.8% general partner interest in the Partnership, and 100% of the IDRs. As of September 30, 2015 , other subsidiaries of Anadarko held 757,619 common units and 11,230,814 Class C units, representing an aggregate 8.4% limited partner interest in the Partnership. As of September 30, 2015 , the public held 78,520,822 common units, representing a 55.2% limited partner interest in the Partnership. Net income per unit for common units. The Partnership’s net income earned on and subsequent to the date of the acquisition of the Partnership assets is allocated to the general partner and the limited partners, including any Class C unitholders, in accordance with their respective weighted-average ownership percentages and, when applicable, giving effect to incentive distributions allocable to the general partner. The Partnership’s net income allocable to the limited partners is net of amortization of the beneficial conversion feature related to the Class C units (see Class C units above) and is allocated between the common and Class C unitholders by applying the provisions of the partnership agreement that govern actual cash distributions and capital account allocations, as if all earnings for the period had been distributed. Net income attributable to the Partnership assets acquired from Anadarko for periods prior to the Partnership’s acquisition of the Partnership assets is not allocated to the limited partners for purposes of calculating net income per common unit. Basic net income per common unit is calculated by dividing the limited partners’ interest in net income attributable to common unitholders by the weighted-average number of common units outstanding during the period. The common units issued in connection with acquisitions and equity offerings are included on a weighted-average basis for periods they were outstanding. Because the Class C units participate in distributions with common units according to a predetermined formula (see Note 3 ), they are considered a participating security and are included in the computation of earnings per unit pursuant to the two-class method. The Class C unit participation right results in a non-contingent transfer of value each time the Partnership declares a distribution. Diluted net income per common unit is calculated by dividing the sum of (i) the limited partners’ interest in net income attributable to common units, and (ii) the limited partners’ interest in net income allocable to the Class C units as a participating security, by the sum of the weighted-average number of common units outstanding plus the dilutive effect of outstanding Class C units. 4. EQUITY AND PARTNERS’ CAPITAL (CONTINUED) The following table illustrates the Partnership’s calculation of net income per unit for common units: Three Months Ended Nine Months Ended thousands except per-unit amounts 2015 2014 2015 2014 Net income attributable to Western Gas Partners, LP $ 161,306 $ 109,159 $ 355,396 $ 299,382 Pre-acquisition net (income) loss allocated to Anadarko — (6,482 ) (1,742 ) (13,282 ) General partner interest in net (income) loss (50,213 ) (31,058 ) (138,121 ) (83,939 ) Limited partners’ interest in net income 111,093 71,619 215,533 202,161 Net income allocable to common units (1) 98,445 71,619 187,650 202,161 Net income allocable to Class C units (1) 12,648 — 27,883 — Limited partners’ interest in net income $ 111,093 $ 71,619 $ 215,533 $ 202,161 Net income per unit Common units - basic $ 0.77 $ 0.60 $ 1.46 $ 1.71 Common units – diluted (2) 0.77 0.60 1.46 1.71 Weighted-average units outstanding Common units – basic 128,575 119,068 128,267 118,326 Class C units (2) 11,161 — 11,042 — Common units – diluted 139,736 119,068 139,309 118,326 (1) Adjusted to reflect amortization for the beneficial conversion feature. See Class C units above for a discussion of the Class C units. (2) Inclusion of Class C units in the calculation would have had an anti-dilutive effect.

Transactions with Affiliates

Transactions with Affiliates	9 Months Ended
	Sep. 30, 2015
Related Party Fees and Other Arrangements, Limited Liability Company (LLC) or Limited Partnership (LP) [Abstract]
Transactions with Affiliates	5. TRANSACTIONS WITH AFFILIATES Affiliate transactions. Revenues from affiliates include amounts earned by the Partnership from services provided to Anadarko as well as from the sale of residue, drip condensate and NGLs to Anadarko. In addition, the Partnership purchases natural gas from an affiliate of Anadarko pursuant to gas purchase agreements. Operation and maintenance expense includes amounts accrued for or paid to affiliates for the operation of the Partnership assets, whether in providing services to affiliates or to third parties, including field labor, measurement and analysis, and other disbursements. A portion of the Partnership’s general and administrative expenses is paid by Anadarko, which results in affiliate transactions pursuant to the reimbursement provisions of the Partnership’s omnibus agreement. Affiliate expenses do not bear a direct relationship to affiliate revenues, and third-party expenses do not bear a direct relationship to third-party revenues. See Note 2 for further information related to contributions of assets to the Partnership by Anadarko. Cash management. Anadarko operates a cash management system whereby excess cash from most of its subsidiaries’ separate bank accounts is generally swept to centralized accounts. Prior to the Partnership’s acquisition of the Partnership assets, third-party sales and purchases related to such assets were received or paid in cash by Anadarko within its centralized cash management system. The outstanding affiliate balances were entirely settled through an adjustment to net investment by Anadarko in connection with the acquisition of the Partnership assets. Subsequent to the acquisition of Partnership assets from Anadarko, transactions related to such assets are cash-settled directly with third parties and with Anadarko affiliates. Chipeta cash settles its transactions directly with third parties and Anadarko, as well as with the other subsidiaries of the Partnership. 5. TRANSACTIONS WITH AFFILIATES (CONTINUED) Note receivable from and Deferred purchase price obligation - Anadarko. Concurrently with the closing of the Partnership’s May 2008 initial public offering, the Partnership loaned $260.0 million to Anadarko in exchange for a 30-year note bearing interest at a fixed annual rate of 6.50% , payable quarterly. The fair value of the note receivable from Anadarko was $288.9 million and $317.8 million at September 30, 2015 , and December 31, 2014 , respectively. The fair value of the note reflects consideration of credit risk and any premium or discount for the differential between the stated interest rate and quarter-end market interest rate, based on quoted market prices of similar debt instruments. Accordingly, the fair value of the note receivable from Anadarko is measured using Level 2 inputs. The consideration to be paid by the Partnership for the March 2015 acquisition of DBJV consists of a cash payment to Anadarko due on March 31, 2020. See Note 2 and Note 9 . Commodity price swap agreements. The Partnership has commodity price swap agreements with Anadarko to mitigate exposure to a substantial majority of the commodity price volatility that would otherwise be present as a result of the purchase and sale of natural gas, condensate or NGLs. Notional volumes for each of the commodity price swap agreements are not specifically defined. Instead, the commodity price swap agreements apply to the actual volume of natural gas, condensate and NGLs purchased and sold at the Hugoton system, the MGR assets and the DJ Basin complex, with various expiration dates through December 2016 . On December 31, 2014, the Partnership’s commodity price swap agreements for the Hilight and Newcastle systems and the Granger complex (excluding the Granger straddle plant) expired without renewal. The commodity price swap agreements do not satisfy the definition of a derivative financial instrument and, therefore, are not required to be measured at fair value. Below is a summary of the fixed price ranges on all of the Partnership’s outstanding commodity price swap agreements as of September 30, 2015 : per barrel except natural gas 2015 2016 Ethane $ 18.41 − 23.41 $ 23.11 Propane 47.08 − 52.99 52.90 Isobutane 62.09 − 74.02 73.89 Normal butane 54.62 − 65.04 64.93 Natural gasoline 72.88 − 81.82 81.68 Condensate 76.47 − 81.82 81.68 Natural gas (per MMBtu) 4.66 − 5.96 4.87 The following table summarizes gains and losses upon settlement of commodity price swap agreements recognized in the consolidated statements of income: Three Months Ended Nine Months Ended thousands 2015 2014 2015 2014 Gains (losses) on commodity price swap agreements related to sales: (1) Natural gas sales $ 5,774 $ 3,179 $ 39,100 $ 1,525 Natural gas liquids sales 33,746 22,737 116,475 66,746 Total 39,520 25,916 155,575 68,271 Losses on commodity price swap agreements related to purchases (2) (23,998 ) (19,533 ) (99,897 ) (38,081 ) Net gains (losses) on commodity price swap agreements $ 15,522 $ 6,383 $ 55,678 $ 30,190 (1) Reported in affiliate natural gas, natural gas liquids and drip condensate sales in the consolidated statements of income in the period in which the related sale is recorded. (2) Reported in cost of product in the consolidated statements of income in the period in which the related purchase is recorded. 5. TRANSACTIONS WITH AFFILIATES (CONTINUED) DJ Basin complex and Hugoton system swap extensions. On June 25, 2015, the Partnership extended its commodity price swap agreements with Anadarko for the DJ Basin complex from July 1, 2015, through December 31, 2015, and for the Hugoton system from October 1, 2015, through December 31, 2015. The table below summarizes the swap prices compared to the forward market prices on the date the commodity price swap extensions were executed. DJ Basin Complex Hugoton System per barrel except natural gas 2015 Swap Prices Market Prices (1) 2015 Swap Prices Market Prices (1) Ethane $ 18.41 $ 1.96 — — Propane 47.08 13.10 — — Isobutane 62.09 19.75 — — Normal butane 54.62 18.99 — — Natural gasoline 72.88 52.59 — — Condensate 76.47 52.59 $ 78.61 $ 32.56 Natural gas (per MMBtu) 5.96 2.75 5.50 2.74 (1) Represents the New York Mercantile Exchange forward strip price as of June 25, 2015, adjusted for location, basis and, in the case of NGLs, transportation and fractionation costs. Revenues or costs attributable to volumes settled during the respective extension period, at the applicable market price in the above table, will be recognized in the consolidated statements of income. The Partnership will also record a capital contribution from Anadarko in the Partnership’s consolidated statement of equity and partners’ capital for the amount by which the swap price exceeds the applicable market price in the above table. For each of the three and nine months ended September 30, 2015 , the capital contribution from Anadarko was $7.9 million . Gas gathering and processing agreements. The Partnership has significant gas gathering and processing arrangements with affiliates of Anadarko on a majority of its systems. The Partnership’s gathering, treating and transportation throughput (excluding equity investment throughput and throughput measured in barrels) attributable to natural gas production owned or controlled by Anadarko was 42% and 46% for the three and nine months ended September 30, 2015 , respectively, and 48% and 49% for the three and nine months ended September 30, 2014 , respectively. The Partnership’s processing throughput (excluding equity investment throughput and throughput measured in barrels) attributable to natural gas production owned or controlled by Anadarko was 47% and 51% for the three and nine months ended September 30, 2015 , respectively, and 58% for each of the three and nine months ended September 30, 2014 . Purchase and sale agreements. The Partnership sells a significant amount of its natural gas, condensate and NGLs to Anadarko Energy Services Company (“AESC”), Anadarko’s marketing affiliate. In addition, the Partnership purchases natural gas, condensate and NGLs from AESC pursuant to purchase agreements. The Partnership’s purchase and sale agreements with AESC are generally one-year contracts, subject to annual renewal. WES LTIP. The general partner awards phantom units under the Western Gas Partners, LP 2008 Long-Term Incentive Plan (“WES LTIP”) primarily to its independent directors, but also from time to time to its executive officers and Anadarko employees performing services for the Partnership. The phantom units awarded to the independent directors vest one year from the grant date, while all other awards are subject to graded vesting over a three -year service period. Compensation expense is recognized over the vesting period and was $0.1 million and $0.4 million for the three and nine months ended September 30, 2015 , respectively, and $0.2 million and $0.5 million for the three and nine months ended September 30, 2014 , respectively. 5. TRANSACTIONS WITH AFFILIATES (CONTINUED) WGP LTIP and Anadarko Incentive Plans. General and administrative expenses included $1.0 million and $3.1 million for the three and nine months ended September 30, 2015 , respectively, and $0.9 million and $2.7 million for the three and nine months ended September 30, 2014 , respectively, of equity-based compensation expense, allocated to the Partnership by Anadarko, for awards granted to the executive officers of the general partner and other employees under the Western Gas Equity Partners, LP 2012 Long-Term Incentive Plan (“WGP LTIP”) and the Anadarko Petroleum Corporation 2008 and 2012 Omnibus Incentive Compensation Plans (collectively referred to as the “Anadarko Incentive Plans”). Of this amount, $2.7 million is reflected as a contribution to partners’ capital in the Partnership’s consolidated statement of equity and partners’ capital for the nine months ended September 30, 2015 . Equipment purchases and sales. The following table summarizes the Partnership’s purchases from and sales to Anadarko of pipe and equipment: Nine Months Ended September 30, 2015 2014 2015 2014 thousands Purchases Sales Cash consideration $ 12,131 $ 16,143 $ 700 $ — Net carrying value 7,411 9,745 366 — Partners’ capital adjustment $ 4,720 $ 6,398 $ 334 $ — Summary of affiliate transactions. The following table summarizes affiliate transactions, which include revenue from affiliates, reimbursement of operating expenses and purchases of natural gas: Three Months Ended Nine Months Ended thousands 2015 2014 2015 2014 Revenues and other (1) $ 247,458 $ 269,632 $ 777,739 $ 769,331 Equity income, net (1) 21,976 19,063 59,137 41,322 Cost of product (1) 35,673 27,034 132,663 85,071 Operation and maintenance (2) 17,662 15,583 50,534 44,961 General and administrative (3) 7,671 7,016 22,556 21,243 Operating expenses 61,006 49,633 205,753 151,275 Interest income (4) 4,225 4,225 12,675 12,675 Interest expense (5) 4,310 — 9,920 — Distributions to unitholders (6) 80,845 60,794 228,893 169,001 (1) Represents amounts earned or incurred on and subsequent to the date of acquisition of the Partnership assets, as well as amounts earned or incurred by Anadarko on a historical basis related to the Partnership assets prior to the acquisition of such assets, recognized under gathering, treating or processing agreements, and purchase and sale agreements. (2) Represents expenses incurred on and subsequent to the date of the acquisition of the Partnership assets, as well as expenses incurred by Anadarko on a historical basis related to the Partnership assets prior to the acquisition of such assets. (3) Represents general and administrative expense incurred on and subsequent to the date of the Partnership’s acquisition of the Partnership assets, as well as a management services fee for reimbursement of expenses incurred by Anadarko for periods prior to the acquisition of the Partnership assets by the Partnership. These amounts include equity-based compensation expense allocated to the Partnership by Anadarko (see WES LTIP and WGP LTIP and Anadarko Incentive Plans within this Note 5 ). (4) Represents interest income recognized on the note receivable from Anadarko. (5) For the three and nine months ended September 30, 2015 , includes accretion expense recognized on the Deferred purchase price obligation - Anadarko for the acquisition of DBJV (see Note 2 and Note 9 ). (6) Represents distributions paid under the partnership agreement (see Note 3 and Note 4 ). Concentration of credit risk. Anadarko was the only customer from whom revenues exceeded 10% of the Partnership’s consolidated revenues for all periods presented in the consolidated statements of income.

Property, Plant and Equipment

Property, Plant and Equipment	9 Months Ended
	Sep. 30, 2015
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	6. PROPERTY, PLANT AND EQUIPMENT A summary of the historical cost of the Partnership’s property, plant and equipment is as follows: thousands Estimated Useful Life September 30, 2015 December 31, 2014 Land n/a $ 3,191 $ 2,884 Gathering systems 3 to 47 years 5,431,716 4,972,892 Pipelines and equipment 15 to 45 years 136,303 151,107 Assets under construction n/a 272,445 483,347 Other 3 to 40 years 19,066 16,420 Total property, plant and equipment 5,862,721 5,626,650 Accumulated depreciation 1,072,799 1,055,207 Net property, plant and equipment $ 4,789,922 $ 4,571,443 The cost of property classified as “Assets under construction” is excluded from capitalized costs being depreciated. These amounts represent property that is not yet suitable to be placed into productive service as of the respective balance sheet date. During 2015, the Partnership recognized impairments of $11.8 million , primarily due to the abandonment of compressors at the MIGC system and the DJ Basin complex, and the cancellation of projects at the Non-Operated Marcellus Interest systems, the DBJV system and the Brasada and Red Desert complexes.

Equity Investments

Equity Investments	9 Months Ended
	Sep. 30, 2015
Equity Method Investments and Joint Ventures [Abstract]
Equity Investments	7. EQUITY INVESTMENTS The following table presents the activity in the Partnership’s equity investments for the nine months ended September 30, 2015 : Equity Investments thousands Fort Union White Cliffs Rendezvous Mont Belvieu JV TEG TEP FRP Total Balance at December 31, 2014 $ 25,933 $ 44,315 $ 56,336 $ 121,337 $ 16,790 $ 198,793 $ 170,988 $ 634,492 Investment earnings (loss), net of amortization 4,831 10,663 1,591 17,256 475 11,691 12,630 59,137 Contributions — 6,081 — (432 ) — 1,520 1,883 9,052 Distributions (4,606 ) (10,227 ) (3,047 ) (17,924 ) (685 ) (11,880 ) (12,276 ) (60,645 ) Distributions in excess of cumulative earnings (1) — (2,584 ) (2,708 ) (1,987 ) (82 ) (4,302 ) (746 ) (12,409 ) Balance at September 30, 2015 $ 26,158 $ 48,248 $ 52,172 $ 118,250 $ 16,498 $ 195,822 $ 172,479 $ 629,627 (1) Distributions in excess of cumulative earnings, classified as investing cash flows in the consolidated statements of cash flows, is calculated on an individual investment basis.

Components of Working Capital

Components of Working Capital	9 Months Ended
	Sep. 30, 2015
Components Of Working Capital [Abstract]
Components of Working Capital	8. COMPONENTS OF WORKING CAPITAL A summary of other current assets is as follows: thousands September 30, 2015 December 31, 2014 Natural gas liquids inventory $ 6,486 $ 5,316 Natural gas imbalance receivables 177 415 Prepaid insurance 2,591 2,443 Other 2,145 1,893 Total other current assets $ 11,399 $ 10,067 A summary of accrued liabilities is as follows: thousands September 30, 2015 December 31, 2014 Accrued capital expenditures $ 70,118 $ 128,856 Accrued plant purchases 26,068 14,023 Accrued interest expense 34,169 24,741 Short-term asset retirement obligations 4,335 1,224 Short-term remediation and reclamation obligations 475 475 Income taxes payable 701 207 Other 2,946 1,263 Total accrued liabilities $ 138,812 $ 170,789

Debt and Interest Expense

Debt and Interest Expense	9 Months Ended
	Sep. 30, 2015
Debt Instruments [Abstract]
Debt and Interest Expense	9. DEBT AND INTEREST EXPENSE At September 30, 2015 , the Partnership’s debt consisted of 5.375% Senior Notes due 2021 (the “2021 Notes”), 4.000% Senior Notes due 2022 (the “2022 Notes”), 2.600% Senior Notes due 2018 (the “2018 Notes”), 5.450% Senior Notes due 2044 (the “2044 Notes”), 3.950% Senior Notes due 2025 (the “2025 Notes”), and borrowings on the senior unsecured revolving credit facility (“RCF”). The following table presents the Partnership’s outstanding debt as of September 30, 2015 , and December 31, 2014 : September 30, 2015 December 31, 2014 thousands Principal Carrying Value Fair Value (1) Principal Carrying Value Fair Value (1) 2021 Notes $ 500,000 $ 496,139 $ 534,860 $ 500,000 $ 495,714 $ 549,530 2022 Notes 670,000 672,662 654,858 670,000 672,930 681,942 2018 Notes 350,000 350,380 350,151 350,000 350,474 352,162 2044 Notes 400,000 393,901 365,196 400,000 393,836 417,619 2025 Notes 500,000 494,107 465,247 — — — RCF 180,000 180,000 180,000 510,000 510,000 510,000 Total long-term debt $ 2,600,000 $ 2,587,189 $ 2,550,312 $ 2,430,000 $ 2,422,954 $ 2,511,253 (1) Fair value is measured using the market approach and Level 2 inputs. 9. DEBT AND INTEREST EXPENSE (CONTINUED) Debt activity. The following table presents the debt activity of the Partnership for the nine months ended September 30, 2015 : thousands Carrying Value Balance at December 31, 2014 $ 2,422,954 RCF borrowings 280,000 Issuance of 2025 Notes 500,000 Repayments of RCF borrowings (610,000 ) Other (5,765 ) Balance at September 30, 2015 $ 2,587,189 Senior Notes. The 2025 Notes issued in June 2015 were offered at a price to the public of 98.789% of the face amount. Including the effects of the issuance and underwriting discounts, the effective interest rate of the 2025 Notes is 4.205% . Interest is paid semi-annually on June 1 and December 1 of each year. Proceeds (net of underwriting discount of $3.3 million , original issue discount and debt issuance costs) were used to repay a portion of the amount outstanding under the RCF. At September 30, 2015 , the Partnership was in compliance with all covenants under the indentures governing its outstanding notes. Revolving credit facility. The interest rate on the RCF, which matures in February 2019, was 1.49% and 1.46% at September 30, 2015 , and September 30, 2014 , respectively. The facility fee rate was 0.20% at September 30, 2015 , and September 30, 2014 . As of September 30, 2015 , the Partnership had $180.0 million of outstanding borrowings, $12.8 million in outstanding letters of credit and $1.0 billion available for borrowing under the RCF. At September 30, 2015 , the Partnership was in compliance with all covenants under the RCF. Interest expense. The following table summarizes the amounts included in interest expense: Three Months Ended Nine Months Ended thousands 2015 2014 2015 2014 Third parties Long-term debt $ 26,972 $ 21,671 $ 75,047 $ 59,251 Amortization of debt issuance costs and commitment fees 1,530 1,107 4,196 3,799 Capitalized interest (1,039 ) (1,900 ) (6,826 ) (7,347 ) Total interest expense – third parties 27,463 20,878 72,417 55,703 Affiliates Deferred purchase price obligation – Anadarko (1) 4,310 — 9,920 — Total interest expense – affiliates 4,310 — 9,920 — Interest expense $ 31,773 $ 20,878 $ 82,337 $ 55,703 (1) See Note 2 for a discussion of the accretion and present value of the Deferred purchase price obligation - Anadarko.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	10. COMMITMENTS AND CONTINGENCIES Litigation and legal proceedings. In March 2011, DCP Midstream, LP (“DCP”) filed a lawsuit against Anadarko and others, including a Partnership subsidiary, Kerr-McGee Gathering, LLC, in Weld County District Court (the “Court”) in Colorado, alleging that Anadarko diverted gas from DCP’s gathering and processing facilities in breach of certain dedication agreements. In addition to various claims against Anadarko, DCP is claiming unjust enrichment and other damages against Kerr-McGee Gathering, LLC, the entity that holds the Wattenberg assets (located in the DJ Basin complex). Anadarko countersued DCP asserting that DCP has not properly allocated values and charges to Anadarko for the gas that DCP gathers and/or processes, and seeks a judgment that DCP has no valid gathering or processing rights to much of the gas production it is claiming, in addition to other claims. The Court has scheduled this matter for trial in June 2016, and the parties are currently engaged in discovery and motion practice. Management does not believe the outcome of this proceeding will have a material effect on the Partnership’s financial condition, results of operations or cash flows. The Partnership intends to vigorously defend this litigation. Furthermore, without regard to the merit of DCP’s claims, management believes that the Partnership has adequate contractual indemnities covering the claims against it in this lawsuit. In addition, from time to time, the Partnership is involved in legal, tax, regulatory and other proceedings in various forums regarding performance, contracts and other matters that arise in the ordinary course of business. Management is not aware of any such proceeding the final disposition of which could have a material adverse effect on the Partnership’s financial condition, results of operations or cash flows. Other commitments. The Partnership has short-term payment obligations, or commitments, related to its capital spending programs, as well as those of its unconsolidated affiliates. As of September 30, 2015 , the Partnership had unconditional payment obligations for services to be rendered or products to be delivered in connection with its capital projects of $42.0 million , the majority of which is expected to be paid in the next twelve months. These commitments relate primarily to the construction of Trains IV, V and VI at the DBM complex and expansion projects at the DBJV system and the DJ Basin complex. Lease commitments. Anadarko, on behalf of the Partnership, has entered into lease agreements for corporate offices, shared field offices and a warehouse supporting the Partnership’s operations, for which Anadarko charges the Partnership rent. The leases for the corporate offices and shared field offices extend through 2017 and 2018, respectively, and the lease for the warehouse extends through February 2017. Rent expense associated with the office, warehouse and equipment leases was $4.9 million and $13.6 million for the three and nine months ended September 30, 2015 , respectively, and $2.4 million and $6.8 million for the three and nine months ended September 30, 2014 , respectively.

Description of Business and B19

Description of Business and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Business combinations policy	Basis of presentation. The consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”). The consolidated financial statements include the accounts of the Partnership and entities in which it holds a controlling financial interest. All significant intercompany transactions have been eliminated. Investments in non-controlled entities over which the Partnership exercises significant influence are accounted for under the equity method. The Partnership proportionately consolidates its 33.75% share of the assets, liabilities, revenues and expenses attributable to the Non-Operated Marcellus Interest systems and Anadarko-Operated Marcellus Interest systems and its 50% share of the assets, liabilities, revenues and expenses attributable to the Newcastle system and the DBJV system (see Note 2 ) in the accompanying consolidated financial statements. The 25% membership interest in Chipeta Processing LLC (“Chipeta”) held by a third-party member is reflected within noncontrolling interest in the consolidated financial statements for all periods presented. In preparing financial statements in accordance with GAAP, management makes informed judgments and estimates that affect the reported amounts of assets, liabilities, revenues and expenses. Management evaluates its estimates and related assumptions regularly, using historical experience and other methods considered reasonable. Changes in facts and circumstances or additional information may result in revised estimates and actual results may differ from these estimates. Effects on the business, financial condition and results of operations resulting from revisions to estimates are recognized when the facts that give rise to the revisions become known. The information furnished herein reflects all normal recurring adjustments which are, in the opinion of management, necessary for a fair presentation of the consolidated financial statements, and certain prior-period amounts have been reclassified to conform to the current-year presentation. Presentation of Partnership assets. The term “Partnership assets” refers to the assets owned and interests accounted for under the equity method (see Note 7 ) by the Partnership as of September 30, 2015 . Because Anadarko controls the Partnership through its ownership and control of WGP, which owns the Partnership’s entire general partner interest, each acquisition of Partnership assets from Anadarko has been considered a transfer of net assets between entities under common control. As such, the Partnership assets acquired from Anadarko were initially recorded at Anadarko’s historic carrying value, which did not correlate to the total acquisition price paid by the Partnership. Further, after an acquisition of Partnership assets from Anadarko, the Partnership may be required to recast its financial statements to include the activities of such Partnership assets from the date of common control. See Note 2 . For those periods requiring recast, the consolidated financial statements for periods prior to the Partnership’s acquisition of the Partnership assets from Anadarko have been prepared from Anadarko’s historical cost-basis accounts and may not necessarily be indicative of the actual results of operations that would have occurred if the Partnership had owned the Partnership assets during the periods reported. Net income attributable to the Partnership assets acquired from Anadarko for periods prior to the Partnership’s acquisition of the Partnership assets is not allocated to the limited partners. DBM acquisition . The DBM acquisition has been accounted for under the acquisition method of accounting. The assets acquired and liabilities assumed in the DBM acquisition were recorded in the consolidated balance sheet at their estimated fair values as of the acquisition date. Results of operations attributable to the DBM acquisition were included in the Partnership’s consolidated statement of income beginning on the acquisition date in the fourth quarter of 2014.
Correction of an immaterial error policy	The Partnership’s unaudited consolidated statements of income reflect the reclassifications of the following amounts, which previously reduced Operation and maintenance expense, to revenues related to Gathering, processing and transportation of natural gas and natural gas liquids: (i) $25.0 million for the nine months ended September 30, 2015 (all of which related to the six months ended June 30, 2015) and (ii) $12.0 million and $28.6 million for the three and nine months ended September 30, 2014 , respectively. Management determined that the third-party producer reimbursements received for electricity purchased by the Partnership is more appropriately classified as revenues, instead of a reduction to Operation and maintenance expense. This correction of an error has no impact to Net income, cash flows, or any non-GAAP metric the Partnership uses to evaluate its operations (see Key Performance Metrics under Item 2 of this Form 10-Q) and is not considered material to the Partnership’s results of operations for the three and nine months ended September 30, 2015 and 2014 . The Partnership will revise its previously reported 2013, 2014 and 2015 consolidated financial statements, and unaudited interim periods therein as applicable, to reflect the reclassification in future filings.
Noncontrolling interest policy	The 25% membership interest in Chipeta Processing LLC (“Chipeta”) held by a third-party member is reflected within noncontrolling interest in the consolidated financial statements for all periods presented.
Net income per common unit policy	Net income per unit for common units. The Partnership’s net income earned on and subsequent to the date of the acquisition of the Partnership assets is allocated to the general partner and the limited partners, including any Class C unitholders, in accordance with their respective weighted-average ownership percentages and, when applicable, giving effect to incentive distributions allocable to the general partner. The Partnership’s net income allocable to the limited partners is net of amortization of the beneficial conversion feature related to the Class C units (see Class C units above) and is allocated between the common and Class C unitholders by applying the provisions of the partnership agreement that govern actual cash distributions and capital account allocations, as if all earnings for the period had been distributed. Net income attributable to the Partnership assets acquired from Anadarko for periods prior to the Partnership’s acquisition of the Partnership assets is not allocated to the limited partners for purposes of calculating net income per common unit. Basic net income per common unit is calculated by dividing the limited partners’ interest in net income attributable to common unitholders by the weighted-average number of common units outstanding during the period. The common units issued in connection with acquisitions and equity offerings are included on a weighted-average basis for periods they were outstanding. Because the Class C units participate in distributions with common units according to a predetermined formula (see Note 3 ), they are considered a participating security and are included in the computation of earnings per unit pursuant to the two-class method. The Class C unit participation right results in a non-contingent transfer of value each time the Partnership declares a distribution. Diluted net income per common unit is calculated by dividing the sum of (i) the limited partners’ interest in net income attributable to common units, and (ii) the limited partners’ interest in net income allocable to the Class C units as a participating security, by the sum of the weighted-average number of common units outstanding plus the dilutive effect of outstanding Class C units.
Fair value policy	Deferred purchase price obligation - Anadarko. The consideration to be paid by the Partnership for the acquisition of DBJV consists of a cash payment to Anadarko due on March 31, 2020. The cash payment will be equal to (a) eight multiplied by the average of the Partnership’s share in the Net Earnings (see definition below) of the DBJV system for the calendar years 2018 and 2019, less (b) the Partnership’s share of all capital expenditures incurred for the DBJV system between March 1, 2015, and February 29, 2020. Net Earnings is defined as all revenues less cost of product, operating expenses and property taxes, in each case attributable to the DBJV system on an accrual basis. As of the acquisition date, the estimated future payment obligation was $282.8 million , which had a net present value of $174.3 million , using a discount rate of 10% . As of September 30, 2015 , the net present value of this obligation was $184.2 million and has been recorded on the consolidated balance sheet under Deferred purchase price obligation - Anadarko. Accretion expense for the three and nine months ended September 30, 2015 , was $4.3 million and $9.9 million , respectively, and has been recorded as a charge to interest expense. The fair value measurement was calculated using Level 3 inputs, which consisted of management’s estimate of the Partnership’s share of forecasted Net Earnings and capital expenditures for the DBJV system. DBM acquisition . The DBM acquisition has been accounted for under the acquisition method of accounting. The assets acquired and liabilities assumed in the DBM acquisition were recorded in the consolidated balance sheet at their estimated fair values as of the acquisition date. Results of operations attributable to the DBM acquisition were included in the Partnership’s consolidated statement of income beginning on the acquisition date in the fourth quarter of 2014. The purchase price allocation is based on an assessment of the fair value of the assets acquired and liabilities assumed in the DBM acquisition using inputs that are not observable in the market and thus represent Level 3 inputs. The fair values of the processing plants, gathering system, and related facilities and equipment are based on market and cost approaches. The fair value of the intangible assets was determined using an income approach. Deferred taxes represent the tax effects of differences in the tax basis and acquisition-date fair value of the assets acquired and liabilities assumed. Class C unit distributions. The Class C units receive quarterly distributions at a rate equivalent to the Partnership’s common units. The distributions are paid in the form of additional Class C units (“PIK Class C units”) until the scheduled conversion date on December 31, 2017 (unless earlier converted), and the Class C units are disregarded with respect to distributions of the Partnership’s available cash until they are converted to common units. The number of additional PIK Class C units to be issued in connection with a distribution payable on the Class C units is determined by dividing the corresponding distribution attributable to the Class C units by the volume-weighted-average price of the Partnership’s common units for the ten days immediately preceding the payment date for the common unit distribution, less a 6% discount. The Partnership records the PIK Class C unit distributions at fair value at the time of issuance. This Level 2 fair value measurement uses the Partnership’s unit price as a significant input in the determination of the fair value. Note receivable from and Deferred purchase price obligation - Anadarko. Concurrently with the closing of the Partnership’s May 2008 initial public offering, the Partnership loaned $260.0 million to Anadarko in exchange for a 30-year note bearing interest at a fixed annual rate of 6.50% , payable quarterly. The fair value of the note receivable from Anadarko was $288.9 million and $317.8 million at September 30, 2015 , and December 31, 2014 , respectively. The fair value of the note reflects consideration of credit risk and any premium or discount for the differential between the stated interest rate and quarter-end market interest rate, based on quoted market prices of similar debt instruments. Accordingly, the fair value of the note receivable from Anadarko is measured using Level 2 inputs.
Use of estimates policy	In preparing financial statements in accordance with GAAP, management makes informed judgments and estimates that affect the reported amounts of assets, liabilities, revenues and expenses. Management evaluates its estimates and related assumptions regularly, using historical experience and other methods considered reasonable. Changes in facts and circumstances or additional information may result in revised estimates and actual results may differ from these estimates. Effects on the business, financial condition and results of operations resulting from revisions to estimates are recognized when the facts that give rise to the revisions become known. The information furnished herein reflects all normal recurring adjustments which are, in the opinion of management, necessary for a fair presentation of the consolidated financial statements, and certain prior-period amounts have been reclassified to conform to the current-year presentation.
Recently issued accounting standards policy	Recently issued accounting standards . The Financial Accounting Standards Board recently issued the following Accounting Standards Updates (“ASUs”): ASU 2015-06, Earnings Per Share (Topic - 260)—Effects on Historical Earnings per Unit of Master Limited Partnership Dropdown Transactions . This ASU contains guidance that addresses the historical earnings per unit presentation for master limited partnerships that apply the two-class method of calculating earnings per unit. When a general partner transfers or “drops down” net assets to a master limited partnership the transaction is accounted for as a transaction between entities under common control and the statements of operations are adjusted retrospectively to reflect the transaction. This ASU specifies that the historical earnings (losses) of a transferred business before the date of a dropdown transaction should be allocated entirely to the general partner, and the previously reported earnings per unit of the limited partners should not change as a result of the dropdown transaction. The ASU also requires additional disclosures about how the rights to the earnings (losses) differ before and after the dropdown transaction occurs for purposes of computing earnings per unit under the two-class method. This ASU is effective for annual and interim periods beginning in 2016 and is required to be adopted using a retrospective approach, with early adoption permitted. While the Partnership believes it is currently in compliance with this ASU, it continues to evaluate the impact of the adoption of this ASU on its consolidated financial statements. ASU 2015-03, Interest—Imputation of Interest (Subtopic 835-30)—Simplifying the Presentation of Debt Issuance Costs and ASU 2015-15, Interest—Imputation of Interest (Subtopic 835-30)—Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements . These ASUs will simplify the presentation of debt issuance costs by requiring such costs, except for those related to revolving credit facilities, to be presented in the balance sheet as a direct deduction from the carrying amount of the related debt liability, rather than as an asset. These ASUs are effective for annual and interim periods beginning in 2016 and are required to be adopted using a retrospective approach, with early adoption permitted. The Partnership does not expect the adoption to have a material impact on its consolidated financial statements. ASU 2015-02, Consolidation—Amendments to the Consolidation Analysis . This ASU will simplify existing requirements by reducing the number of acceptable consolidation models and placing more emphasis on risk of loss when determining a controlling financial interest. The provisions will affect how limited partnerships and similar entities are assessed for consolidation, including the elimination of the presumption that a general partner should consolidate a limited partnership. This ASU is effective for annual and interim periods beginning in 2016 and is required to be adopted using a retrospective or modified retrospective approach, with early adoption permitted. The Partnership is evaluating the impact of the adoption of this ASU on its consolidated financial statements. ASU 2014-09, Revenue from Contracts with Customers . This ASU supersedes the revenue recognition requirements in Topic 605, Revenue Recognition , and industry-specific guidance in Subtopic 932-605, Extractive Activities—Oil and Gas—Revenue Recognition , and requires an entity to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration the entity expects to be entitled to in exchange for those goods or services. The effective date for ASU 2014-09 was delayed through the issuance of ASU 2015-14, Revenue from Contracts with Customers—Deferral of the Effective Date, to annual and interim periods beginning in 2018 and is required to be adopted using one of two retrospective application methods, with early adoption permitted in 2017. The Partnership is evaluating the impact of the adoption of this ASU on its consolidated financial statements

Description of Business and B20

Description of Business and Basis of Presentation (Tables)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Assets and Investments Table	As of September 30, 2015 , the Partnership’s assets and investments accounted for under the equity method consisted of the following: Owned and Operated Operated Interests Non-Operated Interests Equity Interests Natural gas gathering systems 12 2 5 2 Natural gas treating facilities 9 4 — 1 Natural gas processing facilities 14 5 — 2 NGL pipelines 3 — — 3 Natural gas pipelines 4 — — — Oil pipelines 1 — — 1

Acquisitions and Divestitures (

Acquisitions and Divestitures (Tables)	9 Months Ended
	Sep. 30, 2015
Property, Plant and Equipment [Abstract]
Acquisitions Table	The following table presents the acquisitions completed by the Partnership during 2015 and 2014 , and identifies the funding sources for such acquisitions: thousands except unit and percent amounts Acquisition Date Percentage Deferred Purchase Price Obligation - Anadarko Borrowings Cash On Hand Common Units Issued to Anadarko Class C Units Issued to Anadarko TEFR Interests (1) 03/03/2014 Various (1) $ — $ 350,000 $ 6,250 308,490 — DBM (2) 11/25/2014 100 % — 475,000 298,327 — 10,913,853 DBJV system (3) 03/02/2015 50 % 174,276 — — — — (1) The Partnership acquired a 20% interest in each of TEG and TEP and a 33.33% interest in FRP from Anadarko. These assets gather and transport NGLs primarily from the Anadarko and Denver-Julesburg (“DJ”) Basins. The interests in these entities are accounted for under the equity method of accounting. In connection with the issuance of the common units, the Partnership issued 6,296 general partner units to the general partner in exchange for the general partner’s proportionate capital contribution of $0.4 million . (2) The Partnership acquired Nuevo Midstream, LLC (“Nuevo”) from a third party. Following the acquisition, the Partnership changed the name of Nuevo to Delaware Basin Midstream, LLC (“DBM”). The assets acquired include cryogenic processing plants, a gas gathering system, and related facilities and equipment, which are collectively referred to as the “DBM complex” and serve production from Reeves, Loving and Culberson Counties, Texas and Eddy and Lea Counties, New Mexico. See DBM acquisition below for further information, including the preliminary allocation of the purchase price. (3) The Partnership acquired Anadarko’s interest in Delaware Basin JV Gathering LLC (“DBJV”), which owns a 50% interest in a gathering system and related facilities (the “DBJV system”). The DBJV system is located in the Delaware Basin in Loving, Ward, Winkler and Reeves Counties, Texas. The Partnership will make a cash payment on March 31, 2020, to Anadarko as consideration for the acquisition of DBJV. The Partnership currently estimates the future payment will be $282.8 million , the net present value of which was $174.3 million as of the acquisition date. See DBJV acquisition—Deferred purchase price obligation - Anadarko below.
Impact to Historical Consolidated Statements of Income Table	The following table presents the impact of the DBJV system on revenues and other, equity income, net and net income as presented in the Partnership’s historical consolidated statements of income: Three Months Ended September 30, 2014 thousands Partnership Historical (1) DBJV System Combined Revenues and other $ 341,282 $ 16,239 $ 357,521 Equity income, net 19,063 — 19,063 Net income 106,540 6,482 113,022 Nine Months Ended September 30, 2014 thousands Partnership Historical (1) DBJV System Combined Revenues and other $ 970,027 $ 46,124 $ 1,016,151 Equity income, net 41,322 — 41,322 Net income 296,149 14,238 310,387 (1) As adjusted for the reclassification described in Note 1 .
Purchase Price Allocation Table	The following is the preliminary allocation of the purchase price as of September 30, 2015 , including $3.5 million of post-closing purchase price adjustments, to the assets acquired and liabilities assumed in the DBM acquisition as of the acquisition date, pending final review of certain support related to the acquired entity’s assets and liabilities: thousands Current assets $ 62,940 Property, plant and equipment 467,171 Goodwill 282,697 Other intangible assets 811,048 Accounts payables (18,621 ) Accrued liabilities (37,360 ) Deferred income taxes (1,342 ) Asset retirement obligations and other (9,060 ) Total purchase price $ 1,557,473

Partnership Distributions (Tabl

Partnership Distributions (Tables)	9 Months Ended
	Sep. 30, 2015
Distributions Made to Members or Limited Partners [Abstract]
Cash Distributions Table	The Board of Directors of the general partner declared the following cash distributions to the Partnership’s common and general partner unitholders for the periods presented: thousands except per-unit amounts Quarters Ended Total Quarterly Distribution per Unit Total Quarterly Cash Distribution Date of Distribution 2014 March 31 $ 0.625 $ 98,749 May 2014 June 30 0.650 105,655 August 2014 September 30 0.675 111,608 November 2014 December 31 0.700 126,044 February 2015 2015 March 31 $ 0.725 $ 133,203 May 2015 June 30 0.750 139,736 August 2015 September 30 (1) 0.775 146,160 November 2015 (1) On October 14, 2015 , the Board of Directors of the Partnership’s general partner declared a cash distribution to the Partnership’s unitholders of $0.775 per unit, or $146.2 million in aggregate, including incentive distributions, but excluding distributions on Class C units (see Class C unit distributions below). The cash distribution is payable on November 12, 2015 , to unitholders of record at the close of business on November 2, 2015 .
PIK Class C Units Distributions Table	The Partnership issued the following PIK Class C units to APC Midstream Holdings, LLC (“AMH”), the holder of the Class C units, for the periods presented: thousands except unit amounts For the Quarters Ended PIK Class C Units Implied Fair Value Date of 2014 December 31 (1) 45,711 $ 3,072 February 2015 2015 March 31 118,230 $ 8,101 May 2015 June 30 153,020 8,721 August 2015 (1) Prorated for the 37 -day period the Class C units were outstanding during the fourth quarter of 2014.

Equity and Partners' Capital (T

Equity and Partners' Capital (Tables)	9 Months Ended
	Sep. 30, 2015
Partners' Capital Notes [Abstract]
Equity Offerings Table	The Partnership completed the following public offerings of its common units during 2015 and 2014, including through its Continuous Offering Programs (“COP”): thousands except unit and per-unit amounts Common Units Issued GP Units Issued (1) Price Per Unit Underwriting Discount and Other Offering Expenses Net Proceeds 2014 $125.0 million COP (2) 1,133,384 23,132 $ 73.48 $ 1,738 $ 83,245 November 2014 equity offering (3) 8,620,153 153,061 70.85 18,615 602,967 2015 $500.0 million COP (4) 873,525 — $ 66.61 $ 805 $ 57,385 (1) Represents general partner units issued to the general partner in exchange for the general partner’s proportionate capital contribution. (2) Represents common and general partner units issued during the year ended December 31, 2014, pursuant to the Partnership’s registration statement filed with the SEC in August 2012 authorizing the issuance of up to an aggregate of $125.0 million of common units (the “$125.0 million COP”). Gross proceeds generated (including the general partner’s proportionate capital contributions) during the year ended December 31, 2014, were $85.0 million . The price per unit in the table above represents an average price for all issuances under the $125.0 million COP during the year ended December 31, 2014. As of December 31, 2014, the Partnership had used all the capacity to issue common units under this registration statement. (3) Includes the issuance of 1,120,153 common units pursuant to the partial exercise of the underwriters’ over-allotment option, the net proceeds from which were $77.0 million . Beginning with this partial exercise, the Partnership’s general partner elected not to make a corresponding capital contribution to maintain its 2.0% interest in the Partnership. (4) Represents common units issued during the nine months ended September 30, 2015 , pursuant to the Partnership’s registration statement filed with the SEC in August 2014 authorizing the issuance of up to an aggregate of $500.0 million of common units (the “$500.0 million COP”). Gross proceeds generated during the three and nine months ended September 30, 2015 , were zero and $58.2 million , respectively. Commissions paid during the three and nine months ended September 30, 2015 , were zero and $0.6 million , respectively. The price per unit in the table above represents an average price for all issuances under the $500.0 million COP during the nine months ended September 30, 2015 .
Limited Partner and General Partner Units Table	The following table summarizes the common, Class C and general partner units issued during the nine months ended September 30, 2015 : Common Units Class C Units General Partner Units Total Balance at December 31, 2014 127,695,130 10,913,853 2,583,068 141,192,051 PIK Class C units — 316,961 — 316,961 Long-Term Incentive Plan award vestings 5,991 — — 5,991 $500.0 million COP 873,525 — — 873,525 Balance at September 30, 2015 128,574,646 11,230,814 2,583,068 142,388,528
Calculation of Net Income Per Unit Table	The following table illustrates the Partnership’s calculation of net income per unit for common units: Three Months Ended Nine Months Ended thousands except per-unit amounts 2015 2014 2015 2014 Net income attributable to Western Gas Partners, LP $ 161,306 $ 109,159 $ 355,396 $ 299,382 Pre-acquisition net (income) loss allocated to Anadarko — (6,482 ) (1,742 ) (13,282 ) General partner interest in net (income) loss (50,213 ) (31,058 ) (138,121 ) (83,939 ) Limited partners’ interest in net income 111,093 71,619 215,533 202,161 Net income allocable to common units (1) 98,445 71,619 187,650 202,161 Net income allocable to Class C units (1) 12,648 — 27,883 — Limited partners’ interest in net income $ 111,093 $ 71,619 $ 215,533 $ 202,161 Net income per unit Common units - basic $ 0.77 $ 0.60 $ 1.46 $ 1.71 Common units – diluted (2) 0.77 0.60 1.46 1.71 Weighted-average units outstanding Common units – basic 128,575 119,068 128,267 118,326 Class C units (2) 11,161 — 11,042 — Common units – diluted 139,736 119,068 139,309 118,326 (1) Adjusted to reflect amortization for the beneficial conversion feature. See Class C units above for a discussion of the Class C units. (2) Inclusion of Class C units in the calculation would have had an anti-dilutive effect.

Transactions with Affiliates (T

Transactions with Affiliates (Tables)	9 Months Ended
	Sep. 30, 2015
Related Party Fees and Other Arrangements, Limited Liability Company (LLC) or Limited Partnership (LP) [Abstract]
Commodity Price Swap Agreements Table	Below is a summary of the fixed price ranges on all of the Partnership’s outstanding commodity price swap agreements as of September 30, 2015 : per barrel except natural gas 2015 2016 Ethane $ 18.41 − 23.41 $ 23.11 Propane 47.08 − 52.99 52.90 Isobutane 62.09 − 74.02 73.89 Normal butane 54.62 − 65.04 64.93 Natural gasoline 72.88 − 81.82 81.68 Condensate 76.47 − 81.82 81.68 Natural gas (per MMBtu) 4.66 − 5.96 4.87
Gains (Losses) on Commodity Price Swap Agreements Table	The following table summarizes gains and losses upon settlement of commodity price swap agreements recognized in the consolidated statements of income: Three Months Ended Nine Months Ended thousands 2015 2014 2015 2014 Gains (losses) on commodity price swap agreements related to sales: (1) Natural gas sales $ 5,774 $ 3,179 $ 39,100 $ 1,525 Natural gas liquids sales 33,746 22,737 116,475 66,746 Total 39,520 25,916 155,575 68,271 Losses on commodity price swap agreements related to purchases (2) (23,998 ) (19,533 ) (99,897 ) (38,081 ) Net gains (losses) on commodity price swap agreements $ 15,522 $ 6,383 $ 55,678 $ 30,190 (1) Reported in affiliate natural gas, natural gas liquids and drip condensate sales in the consolidated statements of income in the period in which the related sale is recorded. (2) Reported in cost of product in the consolidated statements of income in the period in which the related purchase is recorded.
Commodity Price Swap Agreements Extensions Table	The table below summarizes the swap prices compared to the forward market prices on the date the commodity price swap extensions were executed. DJ Basin Complex Hugoton System per barrel except natural gas 2015 Swap Prices Market Prices (1) 2015 Swap Prices Market Prices (1) Ethane $ 18.41 $ 1.96 — — Propane 47.08 13.10 — — Isobutane 62.09 19.75 — — Normal butane 54.62 18.99 — — Natural gasoline 72.88 52.59 — — Condensate 76.47 52.59 $ 78.61 $ 32.56 Natural gas (per MMBtu) 5.96 2.75 5.50 2.74 (1) Represents the New York Mercantile Exchange forward strip price as of June 25, 2015, adjusted for location, basis and, in the case of NGLs, transportation and fractionation costs.
Related Party Transactions Tables	The following table summarizes the Partnership’s purchases from and sales to Anadarko of pipe and equipment: Nine Months Ended September 30, 2015 2014 2015 2014 thousands Purchases Sales Cash consideration $ 12,131 $ 16,143 $ 700 $ — Net carrying value 7,411 9,745 366 — Partners’ capital adjustment $ 4,720 $ 6,398 $ 334 $ — The following table summarizes affiliate transactions, which include revenue from affiliates, reimbursement of operating expenses and purchases of natural gas: Three Months Ended Nine Months Ended thousands 2015 2014 2015 2014 Revenues and other (1) $ 247,458 $ 269,632 $ 777,739 $ 769,331 Equity income, net (1) 21,976 19,063 59,137 41,322 Cost of product (1) 35,673 27,034 132,663 85,071 Operation and maintenance (2) 17,662 15,583 50,534 44,961 General and administrative (3) 7,671 7,016 22,556 21,243 Operating expenses 61,006 49,633 205,753 151,275 Interest income (4) 4,225 4,225 12,675 12,675 Interest expense (5) 4,310 — 9,920 — Distributions to unitholders (6) 80,845 60,794 228,893 169,001 (1) Represents amounts earned or incurred on and subsequent to the date of acquisition of the Partnership assets, as well as amounts earned or incurred by Anadarko on a historical basis related to the Partnership assets prior to the acquisition of such assets, recognized under gathering, treating or processing agreements, and purchase and sale agreements. (2) Represents expenses incurred on and subsequent to the date of the acquisition of the Partnership assets, as well as expenses incurred by Anadarko on a historical basis related to the Partnership assets prior to the acquisition of such assets. (3) Represents general and administrative expense incurred on and subsequent to the date of the Partnership’s acquisition of the Partnership assets, as well as a management services fee for reimbursement of expenses incurred by Anadarko for periods prior to the acquisition of the Partnership assets by the Partnership. These amounts include equity-based compensation expense allocated to the Partnership by Anadarko (see WES LTIP and WGP LTIP and Anadarko Incentive Plans within this Note 5 ). (4) Represents interest income recognized on the note receivable from Anadarko. (5) For the three and nine months ended September 30, 2015 , includes accretion expense recognized on the Deferred purchase price obligation - Anadarko for the acquisition of DBJV (see Note 2 and Note 9 ). (6) Represents distributions paid under the partnership agreement (see Note 3 and Note 4 ).

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	9 Months Ended
	Sep. 30, 2015
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment Table	A summary of the historical cost of the Partnership’s property, plant and equipment is as follows: thousands Estimated Useful Life September 30, 2015 December 31, 2014 Land n/a $ 3,191 $ 2,884 Gathering systems 3 to 47 years 5,431,716 4,972,892 Pipelines and equipment 15 to 45 years 136,303 151,107 Assets under construction n/a 272,445 483,347 Other 3 to 40 years 19,066 16,420 Total property, plant and equipment 5,862,721 5,626,650 Accumulated depreciation 1,072,799 1,055,207 Net property, plant and equipment $ 4,789,922 $ 4,571,443

Equity Investments (Tables)

Equity Investments (Tables)	9 Months Ended
	Sep. 30, 2015
Equity Method Investments and Joint Ventures [Abstract]
Equity Investments Table	The following table presents the activity in the Partnership’s equity investments for the nine months ended September 30, 2015 : Equity Investments thousands Fort Union White Cliffs Rendezvous Mont Belvieu JV TEG TEP FRP Total Balance at December 31, 2014 $ 25,933 $ 44,315 $ 56,336 $ 121,337 $ 16,790 $ 198,793 $ 170,988 $ 634,492 Investment earnings (loss), net of amortization 4,831 10,663 1,591 17,256 475 11,691 12,630 59,137 Contributions — 6,081 — (432 ) — 1,520 1,883 9,052 Distributions (4,606 ) (10,227 ) (3,047 ) (17,924 ) (685 ) (11,880 ) (12,276 ) (60,645 ) Distributions in excess of cumulative earnings (1) — (2,584 ) (2,708 ) (1,987 ) (82 ) (4,302 ) (746 ) (12,409 ) Balance at September 30, 2015 $ 26,158 $ 48,248 $ 52,172 $ 118,250 $ 16,498 $ 195,822 $ 172,479 $ 629,627 (1) Distributions in excess of cumulative earnings, classified as investing cash flows in the consolidated statements of cash flows, is calculated on an individual investment basis.

Components of Working Capital (

Components of Working Capital (Tables)	9 Months Ended
	Sep. 30, 2015
Components Of Working Capital [Abstract]
Other Current Assets Table	A summary of other current assets is as follows: thousands September 30, 2015 December 31, 2014 Natural gas liquids inventory $ 6,486 $ 5,316 Natural gas imbalance receivables 177 415 Prepaid insurance 2,591 2,443 Other 2,145 1,893 Total other current assets $ 11,399 $ 10,067
Accrued Liabilities Table	A summary of accrued liabilities is as follows: thousands September 30, 2015 December 31, 2014 Accrued capital expenditures $ 70,118 $ 128,856 Accrued plant purchases 26,068 14,023 Accrued interest expense 34,169 24,741 Short-term asset retirement obligations 4,335 1,224 Short-term remediation and reclamation obligations 475 475 Income taxes payable 701 207 Other 2,946 1,263 Total accrued liabilities $ 138,812 $ 170,789

Debt and Interest Expense (Tabl

Debt and Interest Expense (Tables)	9 Months Ended
	Sep. 30, 2015
Debt Instruments [Abstract]
Debt Outstanding and Debt Activity Tables	The following table presents the Partnership’s outstanding debt as of September 30, 2015 , and December 31, 2014 : September 30, 2015 December 31, 2014 thousands Principal Carrying Value Fair Value (1) Principal Carrying Value Fair Value (1) 2021 Notes $ 500,000 $ 496,139 $ 534,860 $ 500,000 $ 495,714 $ 549,530 2022 Notes 670,000 672,662 654,858 670,000 672,930 681,942 2018 Notes 350,000 350,380 350,151 350,000 350,474 352,162 2044 Notes 400,000 393,901 365,196 400,000 393,836 417,619 2025 Notes 500,000 494,107 465,247 — — — RCF 180,000 180,000 180,000 510,000 510,000 510,000 Total long-term debt $ 2,600,000 $ 2,587,189 $ 2,550,312 $ 2,430,000 $ 2,422,954 $ 2,511,253 (1) Fair value is measured using the market approach and Level 2 inputs. 9. DEBT AND INTEREST EXPENSE (CONTINUED) Debt activity. The following table presents the debt activity of the Partnership for the nine months ended September 30, 2015 : thousands Carrying Value Balance at December 31, 2014 $ 2,422,954 RCF borrowings 280,000 Issuance of 2025 Notes 500,000 Repayments of RCF borrowings (610,000 ) Other (5,765 ) Balance at September 30, 2015 $ 2,587,189
Interest Expense Table	The following table summarizes the amounts included in interest expense: Three Months Ended Nine Months Ended thousands 2015 2014 2015 2014 Third parties Long-term debt $ 26,972 $ 21,671 $ 75,047 $ 59,251 Amortization of debt issuance costs and commitment fees 1,530 1,107 4,196 3,799 Capitalized interest (1,039 ) (1,900 ) (6,826 ) (7,347 ) Total interest expense – third parties 27,463 20,878 72,417 55,703 Affiliates Deferred purchase price obligation – Anadarko (1) 4,310 — 9,920 — Total interest expense – affiliates 4,310 — 9,920 — Interest expense $ 31,773 $ 20,878 $ 82,337 $ 55,703 (1) See Note 2 for a discussion of the accretion and present value of the Deferred purchase price obligation - Anadarko.

Description of Business and B29

Description of Business and Basis of Presentation - Asset Table (Details)	Sep. 30, 2015unit
Operated [Member] | Natural Gas Gathering Systems [Member]
Assets [Line Items]
Assets, number of units	12
Operated [Member] | Natural Gas Treating Facilities [Member]
Assets [Line Items]
Assets, number of units	9
Operated [Member] | Natural Gas Processing Facilities [Member]
Assets [Line Items]
Assets, number of units	14
Operated [Member] | Natural Gas Liquids Pipelines [Member]
Assets [Line Items]
Assets, number of units	3
Operated [Member] | Natural Gas Pipelines [Member]
Assets [Line Items]
Assets, number of units	4
Operated [Member] | Oil Pipelines [Member]
Assets [Line Items]
Assets, number of units	1
Operated Interests [Member] | Natural Gas Gathering Systems [Member]
Assets [Line Items]
Assets, number of units	2
Operated Interests [Member] | Natural Gas Treating Facilities [Member]
Assets [Line Items]
Assets, number of units	4
Operated Interests [Member] | Natural Gas Processing Facilities [Member]
Assets [Line Items]
Assets, number of units	5
Non-Operated Interests [Member] | Natural Gas Gathering Systems [Member]
Assets [Line Items]
Assets, number of units	5
Equity Interests [Member] | Natural Gas Gathering Systems [Member]
Assets [Line Items]
Assets, number of units	2
Equity Interests [Member] | Natural Gas Treating Facilities [Member]
Assets [Line Items]
Assets, number of units	1
Equity Interests [Member] | Natural Gas Processing Facilities [Member]
Assets [Line Items]
Assets, number of units	2
Equity Interests [Member] | Natural Gas Liquids Pipelines [Member]
Assets [Line Items]
Assets, number of units	3
Equity Interests [Member] | Oil Pipelines [Member]
Assets [Line Items]
Assets, number of units	1

Description of Business and B30

Description of Business and Basis of Presentation - Additional Information (Details) - USD ($) $ in Millions	Mar. 02, 2015	[1]	Nov. 30, 2014	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
General partner's interest			2.00%
Operating Income (Loss) [Member] | Restatement Adjustment [Member]
Correction of an immaterial error				$ 12	$ 25	$ 28.6
Incentive Distribution Rights [Member] | Western Gas Equity Partners, LP [Member]
General partner's interest					100.00%
General Partner [Member] | Western Gas Equity Partners, LP [Member]
Ownership interest					100.00%
Non-Operated Marcellus Interest [Member]
Ownership interest					33.75%
Anadarko-Operated Marcellus Interest [Member]
Ownership interest					33.75%
Newcastle [Member]
Ownership interest					50.00%
Delaware Basin JV Gathering LLC [Member]
Ownership interest	50.00%				50.00%
Chipeta Processing Limited Liability Company [Member]
Ownership interest by noncontrolling owner					25.00%
Fort Union [Member]
Equity investment ownership					14.81%
Rendezvous [Member]
Equity investment ownership					22.00%
White Cliffs [Member]
Equity investment ownership					10.00%
Mont Belvieu JV [Member]
Equity investment ownership					25.00%
Texas Express Gathering LLC [Member]
Equity investment ownership					20.00%
Texas Express Pipeline LLC [Member]
Equity investment ownership					20.00%
Front Range Pipeline LLC [Member]
Equity investment ownership					33.33%
[1]	The Partnership acquired Anadarko’s interest in Delaware Basin JV Gathering LLC (“DBJV”), which owns a 50% interest in a gathering system and related facilities (the “DBJV system”). The DBJV system is located in the Delaware Basin in Loving, Ward, Winkler and Reeves Counties, Texas. The Partnership will make a cash payment on March 31, 2020, to Anadarko as consideration for the acquisition of DBJV. The Partnership currently estimates the future payment will be $282.8 million, the net present value of which was $174.3 million as of the acquisition date. See DBJV acquisition—Deferred purchase price obligation - Anadarko below.

Acquisitions and Divestitures -

Acquisitions and Divestitures - Acquisitions Table (Details) - USD ($) $ in Thousands		Mar. 02, 2015		Nov. 25, 2014	Mar. 03, 2014	Nov. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	[1]	Dec. 31, 2014
Business Acquisition [Line Items]
Borrowings							$ 769,606	$ 1,136,878
Units issued							316,961
Table Text Block Supplement [Abstract]
General partner units issued							2,583,068			2,583,068
Affiliates [Member]
Business Acquisition [Line Items]
Cash on hand							$ 12,131	$ 372,393
Class C Units [Member]
Business Acquisition [Line Items]
Units issued							316,961
Table Text Block Supplement [Abstract]
Proceeds from the issuance of units						$ 750,000
General Partner [Member]
Business Acquisition [Line Items]
Units issued	[2],[3]					153,061
Texas Express and Front Range [Member]
Business Acquisition [Line Items]
Borrowings	[4]				$ 350,000
Cash on hand	[4]				$ 6,250
Table Text Block Supplement [Abstract]
General partner units issued					6,296
Texas Express and Front Range [Member] | Common Units [Member]
Business Acquisition [Line Items]
Common units issued	[4]				308,490
Texas Express and Front Range [Member] | General Partner [Member]
Table Text Block Supplement [Abstract]
Proceeds from the issuance of units					$ 400
Texas Express Pipeline LLC [Member]
Table Text Block Supplement [Abstract]
Equity investment ownership					20.00%
Texas Express Gathering LLC [Member]
Table Text Block Supplement [Abstract]
Equity investment ownership					20.00%
Front Range Pipeline LLC [Member]
Table Text Block Supplement [Abstract]
Equity investment ownership					33.33%
Delaware Basin Midstream LLC [Member]
Business Acquisition [Line Items]
Percentage acquired	[5]			100.00%
Borrowings	[5]			$ 475,000
Cash on hand	[5]			$ 298,327
Delaware Basin Midstream LLC [Member] | Class C Units [Member]
Business Acquisition [Line Items]
Units issued	[5]			10,913,853
Delaware Basin JV Gathering LLC [Member]
Business Acquisition [Line Items]
Percentage acquired		50.00%	[6]				50.00%
Delaware Basin JV Gathering LLC [Member] | Deferred Purchase Price Obligation - Anadarko [Member] | Affiliates [Member] | Level 3 inputs [Member]
Business Acquisition [Line Items]
Deferred purchase price obligation to Anadarko - acquisition date value	[6]	$ 174,276
Table Text Block Supplement [Abstract]
Deferred purchase price obligation to Anadarko - future value		$ 282,800
[1]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.
[2]	Includes the issuance of 1,120,153 common units pursuant to the partial exercise of the underwriters’ over-allotment option, the net proceeds from which were $77.0 million. Beginning with this partial exercise, the Partnership’s general partner elected not to make a corresponding capital contribution to maintain its 2.0% interest in the Partnership.
[3]	Represents general partner units issued to the general partner in exchange for the general partner’s proportionate capital contribution.
[4]	The Partnership acquired a 20% interest in each of TEG and TEP and a 33.33% interest in FRP from Anadarko. These assets gather and transport NGLs primarily from the Anadarko and Denver-Julesburg (“DJ”) Basins. The interests in these entities are accounted for under the equity method of accounting. In connection with the issuance of the common units, the Partnership issued 6,296 general partner units to the general partner in exchange for the general partner’s proportionate capital contribution of $0.4 million.
[5]	The Partnership acquired Nuevo Midstream, LLC (“Nuevo”) from a third party. Following the acquisition, the Partnership changed the name of Nuevo to Delaware Basin Midstream, LLC (“DBM”). The assets acquired include cryogenic processing plants, a gas gathering system, and related facilities and equipment, which are collectively referred to as the “DBM complex” and serve production from Reeves, Loving and Culberson Counties, Texas and Eddy and Lea Counties, New Mexico. See DBM acquisition below for further information, including the preliminary allocation of the purchase price.
[6]	The Partnership acquired Anadarko’s interest in Delaware Basin JV Gathering LLC (“DBJV”), which owns a 50% interest in a gathering system and related facilities (the “DBJV system”). The DBJV system is located in the Delaware Basin in Loving, Ward, Winkler and Reeves Counties, Texas. The Partnership will make a cash payment on March 31, 2020, to Anadarko as consideration for the acquisition of DBJV. The Partnership currently estimates the future payment will be $282.8 million, the net present value of which was $174.3 million as of the acquisition date. See DBJV acquisition—Deferred purchase price obligation - Anadarko below.

Acquisitions and Divestitures32

Acquisitions and Divestitures - Impact to Historical Consolidated Statements of Income Table (Details) - USD ($) $ in Thousands		3 Months Ended			9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014		Sep. 30, 2015		Sep. 30, 2014
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenues and other		$ 385,101	$ 357,521	[1]	$ 1,190,082		$ 1,016,151	[1]
Equity income, net	[2],[3]	21,976	19,063	[1]	59,137	[4]	41,322	[1],[4]
Net income		$ 163,494	113,022	[1]	$ 363,626		310,387	[1]
Delaware Basin JV Gathering LLC [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenues and other			16,239				46,124
Equity income, net			0				0
Net income			6,482				14,238
Partnership Historical [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenues and other	[5]		341,282				970,027
Equity income, net	[5]		19,063				41,322
Net income	[5]		$ 106,540				$ 296,149
[1]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.
[2]	Income earned from equity investments is classified as affiliate. See Note 1.
[3]	Represents amounts earned or incurred on and subsequent to the date of acquisition of the Partnership assets, as well as amounts earned or incurred by Anadarko on a historical basis related to the Partnership assets prior to the acquisition of such assets, recognized under gathering, treating or processing agreements, and purchase and sale agreements.
[4]	Income earned on, distributions from and contributions to equity investments are classified as affiliate. See Note 1.
[5]	As adjusted for the reclassification described in Note 1.

Acquisitions and Divestitures33

Acquisitions and Divestitures - Purchase Price Allocation Table (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	[1]
Business Acquisition [Line Items]
Goodwill	$ 387,633	$ 389,087
Delaware Basin Midstream LLC [Member] | Level 3 inputs [Member]
Business Acquisition [Line Items]
Current assets	62,940
Property, plant and equipment	467,171
Goodwill	282,697
Other intangible assets	811,048
Accounts payables	(18,621)
Accrued liabilities	(37,360)
Deferred income taxes	(1,342)
Asset retirement obligations and other	(9,060)
Total purchase price	$ 1,557,473
[1]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.

Acquisitions and Divestitures34

Acquisitions and Divestitures - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014		Mar. 02, 2015	Dec. 31, 2014	[2]
Property, Plant and Equipment [Line Items]
Deferred purchase price obligation - Anadarko	[1]	$ 184,196		$ 184,196				$ 0
Gain on divestiture, net		77,244	$ 0	77,244	$ 0	[3]
Dew and Pinnacle Systems [Member]
Property, Plant and Equipment [Line Items]
Proceeds from the sale of assets				146,700
Gain on divestiture, net				77,200
Delaware Basin Midstream LLC [Member]
Property, Plant and Equipment [Line Items]
Post-closing purchase price adjustments				3,500
Affiliates [Member]
Property, Plant and Equipment [Line Items]
Proceeds from the sale of assets				700	0	[3]
Deferred Purchase Price Obligation - Anadarko [Member] | Affiliates [Member]
Property, Plant and Equipment [Line Items]
Interest expense, related party	[4]	4,310	$ 0	$ 9,920	$ 0
Deferred Purchase Price Obligation - Anadarko [Member] | Affiliates [Member] | Delaware Basin JV Gathering LLC [Member]
Property, Plant and Equipment [Line Items]
Discount rate percentage				10.00%
Deferred purchase price obligation - Anadarko		184,200		$ 184,200
Interest expense, related party		$ 4,300		$ 9,900
Level 3 inputs [Member] | Deferred Purchase Price Obligation - Anadarko [Member] | Affiliates [Member] | Delaware Basin JV Gathering LLC [Member]
Property, Plant and Equipment [Line Items]
Deferred purchase price obligation to Anadarko - future value							$ 282,800
Deferred purchase price obligation to Anadarko - acquisition date value	[5]						$ 174,276
[1]	See Note 2.
[2]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.
[3]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.
[4]	See Note 2 for a discussion of the accretion and present value of the Deferred purchase price obligation - Anadarko.
[5]	The Partnership acquired Anadarko’s interest in Delaware Basin JV Gathering LLC (“DBJV”), which owns a 50% interest in a gathering system and related facilities (the “DBJV system”). The DBJV system is located in the Delaware Basin in Loving, Ward, Winkler and Reeves Counties, Texas. The Partnership will make a cash payment on March 31, 2020, to Anadarko as consideration for the acquisition of DBJV. The Partnership currently estimates the future payment will be $282.8 million, the net present value of which was $174.3 million as of the acquisition date. See DBJV acquisition—Deferred purchase price obligation - Anadarko below.

Partnership Distributions - Cas

Partnership Distributions - Cash Distributions Table (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Sep. 30, 2015	[1]	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014
Distributions Made to Members or Limited Partners [Abstract]
Total quarterly distribution per unit	$ 0.775		$ 0.750	$ 0.725	$ 0.700	$ 0.675	$ 0.650	$ 0.625
Total quarterly cash distribution	$ 146,160		$ 139,736	$ 133,203	$ 126,044	$ 111,608	$ 105,655	$ 98,749
[1]	On October 14, 2015, the Board of Directors of the Partnership’s general partner declared a cash distribution to the Partnership’s unitholders of $0.775 per unit, or $146.2 million in aggregate, including incentive distributions, but excluding distributions on Class C units (see Class C unit distributions below). The cash distribution is payable on November 12, 2015, to unitholders of record at the close of business on November 2, 2015.

Partnership Distributions - PIK

Partnership Distributions - PIK Class C Units Distributions Table (Details) - Class C Units [Member] - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014
Distribution Made to Limited Partner [Line Items]
PIK Class C units	153,020	118,230	45,711	[1]
Implied fair value	$ 8,721	$ 8,101	$ 3,072	[1]
Table Text Block Supplement [Abstract]
Number of days in prorated period			37 days
[1]	Prorated for the 37-day period the Class C units were outstanding during the fourth quarter of 2014.

Partnership Distributions - Add

Partnership Distributions - Additional Information (Details)	9 Months Ended
	Sep. 30, 2015
Distribution Made to Limited Partner [Line Items]
Partnership agreement day requirement of distribution of available cash	45 days
Class C Units [Member]
Distribution Made to Limited Partner [Line Items]
Discount rate percentage	6.00%

Equity and Partners' Capital -

Equity and Partners' Capital - Equity Offerings Table (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended	9 Months Ended	12 Months Ended
		Nov. 30, 2014	Sep. 30, 2015	Sep. 30, 2015	Dec. 31, 2014	Aug. 31, 2014	Aug. 31, 2012
Capital Unit [Line Items]
Units issued				316,961
Price per unit	[1]	$ 70.85
Underwriting discount and other offering expenses	[1]	$ 18,615
Net proceeds	[1]	$ 602,967
Table Text Block Supplement [Abstract]
General partner's interest		2.00%
Option On Securities [Member]
Capital Unit [Line Items]
Net proceeds		$ 77,000
125 Million COP [Member]
Capital Unit [Line Items]
Average price per unit	[2]				$ 73.48
Underwriting discount and other offering expenses	[2]				$ 1,738
Net proceeds	[2]				83,245
Table Text Block Supplement [Abstract]
Maximum aggregate principal of common units							$ 125,000
Gross proceeds					$ 85,000
500 Million COP [Member]
Capital Unit [Line Items]
Common units issued				873,525
Average price per unit	[3]			$ 66.61
Underwriting discount and other offering expenses	[3]		$ 805	$ 805
Net proceeds	[3]			57,385
Table Text Block Supplement [Abstract]
Maximum aggregate principal of common units						$ 500,000
Gross proceeds			0	58,200
Commissions paid			$ 0	$ 600
Common Units [Member]
Capital Unit [Line Items]
Common units issued	[1]	8,620,153
Common Units [Member] | Option On Securities [Member]
Capital Unit [Line Items]
Common units issued		1,120,153
Common Units [Member] | 125 Million COP [Member]
Capital Unit [Line Items]
Common units issued	[2]				1,133,384
Common Units [Member] | 500 Million COP [Member]
Capital Unit [Line Items]
Common units issued	[3]			873,525
General Partner [Member]
Capital Unit [Line Items]
Units issued	[1],[4]	153,061
General Partner [Member] | 125 Million COP [Member]
Capital Unit [Line Items]
Units issued	[2],[4]				23,132
[1]	Includes the issuance of 1,120,153 common units pursuant to the partial exercise of the underwriters’ over-allotment option, the net proceeds from which were $77.0 million. Beginning with this partial exercise, the Partnership’s general partner elected not to make a corresponding capital contribution to maintain its 2.0% interest in the Partnership.
[2]	Represents common and general partner units issued during the year ended December 31, 2014, pursuant to the Partnership’s registration statement filed with the SEC in August 2012 authorizing the issuance of up to an aggregate of $125.0 million of common units (the “$125.0 million COP”). Gross proceeds generated (including the general partner’s proportionate capital contributions) during the year ended December 31, 2014, were $85.0 million. The price per unit in the table above represents an average price for all issuances under the $125.0 million COP during the year ended December 31, 2014. As of December 31, 2014, the Partnership had used all the capacity to issue common units under this registration statement.
[3]	Represents common units issued during the nine months ended September 30, 2015, pursuant to the Partnership’s registration statement filed with the SEC in August 2014 authorizing the issuance of up to an aggregate of $500.0 million of common units (the “$500.0 million COP”). Gross proceeds generated during the three and nine months ended September 30, 2015, were zero and $58.2 million, respectively. Commissions paid during the three and nine months ended September 30, 2015, were zero and $0.6 million, respectively. The price per unit in the table above represents an average price for all issuances under the $500.0 million COP during the nine months ended September 30, 2015.
[4]	Represents general partner units issued to the general partner in exchange for the general partner’s proportionate capital contribution.

Equity and Partners' Capital 39

Equity and Partners' Capital - Limited Partner and General Partner Units Table (Details) - shares		1 Months Ended	9 Months Ended
		Nov. 30, 2014	Sep. 30, 2015
Capital Unit [Line Items]
Balance			141,192,051
PIK Class C units			316,961
Long-Term Incentive Plan award vestings			5,991
Balance			142,388,528
500 Million COP [Member]
Capital Unit [Line Items]
Offering			873,525
Common Units [Member]
Capital Unit [Line Items]
Balance			127,695,130
Long-Term Incentive Plan award vestings			5,991
Offering	[1]	8,620,153
Balance			128,574,646
Common Units [Member] | 500 Million COP [Member]
Capital Unit [Line Items]
Offering	[2]		873,525
Class C Units [Member]
Capital Unit [Line Items]
Balance			10,913,853
PIK Class C units			316,961
Balance			11,230,814
General Partner [Member]
Capital Unit [Line Items]
Balance			2,583,068
PIK Class C units	[1],[3]	153,061
Balance			2,583,068
[1]	Includes the issuance of 1,120,153 common units pursuant to the partial exercise of the underwriters’ over-allotment option, the net proceeds from which were $77.0 million. Beginning with this partial exercise, the Partnership’s general partner elected not to make a corresponding capital contribution to maintain its 2.0% interest in the Partnership.
[2]	Represents common units issued during the nine months ended September 30, 2015, pursuant to the Partnership’s registration statement filed with the SEC in August 2014 authorizing the issuance of up to an aggregate of $500.0 million of common units (the “$500.0 million COP”). Gross proceeds generated during the three and nine months ended September 30, 2015, were zero and $58.2 million, respectively. Commissions paid during the three and nine months ended September 30, 2015, were zero and $0.6 million, respectively. The price per unit in the table above represents an average price for all issuances under the $500.0 million COP during the nine months ended September 30, 2015.
[3]	Represents general partner units issued to the general partner in exchange for the general partner’s proportionate capital contribution.

Equity and Partners' Capital 40

Equity and Partners' Capital - Calculation of Net Income Per Unit Table (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended			9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014		Sep. 30, 2015	Sep. 30, 2014
Earnings Per Unit [Line Items]
Net income attributable to Western Gas Partners, LP		$ 161,306	$ 109,159	[1]	$ 355,396	$ 299,382	[1]
Pre-acquisition net (income) loss allocated to Anadarko		0	(6,482)	[1]	(1,742)	(13,282)	[1]
General partner interest in net (income) loss	[2]	(50,213)	(31,058)	[1]	(138,121)	(83,939)	[1]
Limited partners' interest in net income	[2]	$ 111,093	$ 71,619	[1]	$ 215,533	$ 202,161	[1]
Net income per common unit - basic	[3]	$ 0.77	$ 0.60	[1]	$ 1.46	$ 1.71	[1]
Net income per common unit - diluted	[3],[4]	$ 0.77	$ 0.60	[1]	$ 1.46	$ 1.71	[1]
Weighted-average limited partnership units outstanding - diluted		139,736	119,068		139,309	118,326
Common Units [Member]
Earnings Per Unit [Line Items]
Limited partners' interest in net income	[5]	$ 98,445	$ 71,619		$ 187,650	$ 202,161
Weighted-average limited partnership units outstanding - basic		128,575	119,068		128,267	118,326
Class C Units [Member]
Earnings Per Unit [Line Items]
Limited partners' interest in net income	[5]	$ 12,648	$ 0		$ 27,883	$ 0
Weighted-average limited partnership units outstanding - basic	[4]	11,161	0		11,042	0
[1]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.
[2]	Represents net income earned on and subsequent to the date of acquisition of the Partnership assets (as defined in Note 1). See Note 4.
[3]	See Note 4 for the calculation of net income per unit.
[4]	Inclusion of Class C units in the calculation would have had an anti-dilutive effect.
[5]	Adjusted to reflect amortization for the beneficial conversion feature. See Class C units above for a discussion of the Class C units.

Equity and Partners' Capital 41

Equity and Partners' Capital - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions		1 Months Ended	9 Months Ended	12 Months Ended
		Nov. 30, 2014	Sep. 30, 2015	Dec. 31, 2014
Schedule Of Investments [Line Items]
Units issued			316,961
Price per unit	[1]	$ 70.85
General partner units owned			2,583,068	2,583,068
General partner's interest		2.00%
Western Gas Equity Partners, LP [Member]
Schedule Of Investments [Line Items]
General partner units owned			2,583,068
General partner's interest			1.80%
Other Subsidiaries Of Anadarko [Member]
Schedule Of Investments [Line Items]
Limited partner ownership interest			8.40%
Class C Units [Member]
Schedule Of Investments [Line Items]
Units issued			316,961
Price per unit		$ 68.72
Proceeds from the issuance of Class C units		$ 750
Beneficial conversion feature of Class C units				$ 34.8
Limited partner units owned			11,230,814	10,913,853
Class C Units [Member] | Other Subsidiaries Of Anadarko [Member]
Schedule Of Investments [Line Items]
Units issued		10,913,853
Limited partner units owned			11,230,814
Class C Units [Member] | Maximum [Member]
Schedule Of Investments [Line Items]
Redeemable option on units		$ 150
Common Units [Member]
Schedule Of Investments [Line Items]
Limited partner units owned			128,574,646	127,695,130
Common Units [Member] | Western Gas Equity Partners, LP [Member]
Schedule Of Investments [Line Items]
Limited partner units owned			49,296,205
Limited partner ownership interest			34.60%
Common Units [Member] | Other Subsidiaries Of Anadarko [Member]
Schedule Of Investments [Line Items]
Limited partner units owned			757,619
Common Units [Member] | Public [Member]
Schedule Of Investments [Line Items]
Limited partner units owned			78,520,822
Limited partner ownership interest			55.20%
Incentive Distribution Rights [Member] | Western Gas Equity Partners, LP [Member]
Schedule Of Investments [Line Items]
General partner's interest			100.00%
[1]	Includes the issuance of 1,120,153 common units pursuant to the partial exercise of the underwriters’ over-allotment option, the net proceeds from which were $77.0 million. Beginning with this partial exercise, the Partnership’s general partner elected not to make a corresponding capital contribution to maintain its 2.0% interest in the Partnership.

Transactions with Affiliates -

Transactions with Affiliates - Commodity Price Swap Agreements Table (Details)	Sep. 30, 2015$ / bbl$ / MMBTU
Ethane [Member] | Year 2016 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	23.11
Ethane [Member] | Minimum [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	18.41
Ethane [Member] | Maximum [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	23.41
Propane [Member] | Year 2016 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	52.90
Propane [Member] | Minimum [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	47.08
Propane [Member] | Maximum [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	52.99
Isobutane [Member] | Year 2016 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	73.89
Isobutane [Member] | Minimum [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	62.09
Isobutane [Member] | Maximum [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	74.02
Normal butane [Member] | Year 2016 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	64.93
Normal butane [Member] | Minimum [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	54.62
Normal butane [Member] | Maximum [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	65.04
Natural gasoline [Member] | Year 2016 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	81.68
Natural gasoline [Member] | Minimum [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	72.88
Natural gasoline [Member] | Maximum [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	81.82
Condensate [Member] | Year 2016 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	81.68
Condensate [Member] | Minimum [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	76.47
Condensate [Member] | Maximum [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	81.82
Natural gas (per MMBtu) [Member] | Year 2016 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price | $ / MMBTU	4.87
Natural gas (per MMBtu) [Member] | Minimum [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price | $ / MMBTU	4.66
Natural gas (per MMBtu) [Member] | Maximum [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price | $ / MMBTU	5.96

Transactions with Affiliates 43

Transactions with Affiliates - Gains (Losses) on Commodity Price Swap Agreements Table (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Gains (losses) on commodity price swap agreements related to sales and purchases
Net gains (losses) on commodity price swap agreements		$ 15,522	$ 6,383	$ 55,678	$ 30,190
Sales [Member]
Gains (losses) on commodity price swap agreements related to sales and purchases
Net gains (losses) on commodity price swap agreements	[1]	39,520	25,916	155,575	68,271
Sales [Member] | Natural Gas [Member]
Gains (losses) on commodity price swap agreements related to sales and purchases
Net gains (losses) on commodity price swap agreements	[1]	5,774	3,179	39,100	1,525
Sales [Member] | Natural Gas Liquids [Member]
Gains (losses) on commodity price swap agreements related to sales and purchases
Net gains (losses) on commodity price swap agreements	[1]	33,746	22,737	116,475	66,746
Cost of Sales [Member]
Gains (losses) on commodity price swap agreements related to sales and purchases
Net gains (losses) on commodity price swap agreements	[2]	$ (23,998)	$ (19,533)	$ (99,897)	$ (38,081)
[1]	Reported in affiliate natural gas, natural gas liquids and drip condensate sales in the consolidated statements of income in the period in which the related sale is recorded.
[2]	Reported in cost of product in the consolidated statements of income in the period in which the related purchase is recorded.

Transactions with Affiliates 44

Transactions with Affiliates - Commodity Price Swap Agreements Extensions Table (Details)	Jun. 25, 2015$ / bbl$ / MMBTU
DJ Basin Complex [Member] | Ethane [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	1.96	[1]
DJ Basin Complex [Member] | Ethane [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	18.41
DJ Basin Complex [Member] | Propane [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	13.10	[1]
DJ Basin Complex [Member] | Propane [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	47.08
DJ Basin Complex [Member] | Isobutane [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	19.75	[1]
DJ Basin Complex [Member] | Isobutane [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	62.09
DJ Basin Complex [Member] | Normal butane [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	18.99	[1]
DJ Basin Complex [Member] | Normal butane [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	54.62
DJ Basin Complex [Member] | Natural gasoline [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	52.59	[1]
DJ Basin Complex [Member] | Natural gasoline [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	72.88
DJ Basin Complex [Member] | Condensate [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	52.59	[1]
DJ Basin Complex [Member] | Condensate [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	76.47
DJ Basin Complex [Member] | Natural gas (per MMBtu) [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price | $ / MMBTU	2.75	[1]
DJ Basin Complex [Member] | Natural gas (per MMBtu) [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price | $ / MMBTU	5.96
Hugoton System [Member] | Condensate [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	32.56	[1]
Hugoton System [Member] | Condensate [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	78.61
Hugoton System [Member] | Natural gas (per MMBtu) [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price | $ / MMBTU	2.74	[1]
Hugoton System [Member] | Natural gas (per MMBtu) [Member] | Year 2015 [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price | $ / MMBTU	5.50
[1]	Represents the New York Mercantile Exchange forward strip price as of June 25, 2015, adjusted for location, basis and, in the case of NGLs, transportation and fractionation costs.

Transactions with Affiliates 45

Transactions with Affiliates - Equipment Purchases and Sales Table (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Related Party Transaction [Line Items]
Partners’ capital adjustment	$ 4,386	$ 6,398	[1]
Affiliates [Member] | Purchases [Member]
Related Party Transaction [Line Items]
Cash consideration - purchases	12,131	16,143
Net carrying value	7,411	9,745
Partners’ capital adjustment	4,720	6,398
Affiliates [Member] | Sales [Member]
Related Party Transaction [Line Items]
Cash consideration - sales	700	0
Net carrying value	366	0
Partners’ capital adjustment	$ (334)	$ 0
[1]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.

Transactions with Affiliates 46

Transactions with Affiliates - Summary Table (Details) - USD ($) $ in Thousands		3 Months Ended			9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014		Sep. 30, 2015		Sep. 30, 2014
Related Party Transaction [Line Items]
Revenues and other		$ 385,101	$ 357,521	[1]	$ 1,190,082		$ 1,016,151	[1]
Equity income, net	[2],[3]	21,976	19,063	[1]	59,137	[4]	41,322	[1],[4]
Cost of product	[5]	127,721	113,217	[1]	414,378		330,926	[1]
Operation and maintenance	[5]	80,633	67,489	[1]	218,640		184,023	[1]
General and administrative	[5]	9,318	8,339	[1]	28,497		25,688	[1]
Operating expenses		291,703	243,115	[1]	889,097		696,647	[1]
Interest income	[6]	4,225	4,225	[1]	12,675		12,675	[1]
Interest expense	[7]	31,773	20,878	[1]	82,337		55,703	[1]
Distributions to unitholders					398,983		297,013	[1]
Affiliates [Member]
Related Party Transaction [Line Items]
Revenues and other	[3]	247,458	269,632	[1]	777,739		769,331	[1]
Cost of product	[3]	35,673	27,034		132,663		85,071
Operation and maintenance	[8]	17,662	15,583		50,534		44,961
General and administrative	[9]	7,671	7,016		22,556		21,243
Operating expenses		61,006	49,633		205,753		151,275
Interest expense	[10]	4,310	0		9,920		0
Distributions to unitholders	[11]	$ 80,845	$ 60,794		$ 228,893		$ 169,001
[1]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.
[2]	Income earned from equity investments is classified as affiliate. See Note 1.
[3]	Represents amounts earned or incurred on and subsequent to the date of acquisition of the Partnership assets, as well as amounts earned or incurred by Anadarko on a historical basis related to the Partnership assets prior to the acquisition of such assets, recognized under gathering, treating or processing agreements, and purchase and sale agreements.
[4]	Income earned on, distributions from and contributions to equity investments are classified as affiliate. See Note 1.
[5]	Cost of product includes product purchases from Anadarko (as defined in Note 1) of $35.7 million and $132.7 million for the three and nine months ended September 30, 2015, respectively, and $27.0 million and $85.1 million for the three and nine months ended September 30, 2014, respectively. Operation and maintenance includes charges from Anadarko of $17.7 million and $50.5 million for the three and nine months ended September 30, 2015, respectively, and $15.6 million and $45.0 million for the three and nine months ended September 30, 2014, respectively. General and administrative includes charges from Anadarko of $7.7 million and $22.6 million for the three and nine months ended September 30, 2015, respectively, and $7.0 million and $21.2 million for the three and nine months ended September 30, 2014, respectively. See Note 5.
[6]	Represents interest income recognized on the note receivable from Anadarko.
[7]	Includes affiliate (as defined in Note 1) interest expense of $4.3 million and $9.9 million for the three and nine months ended September 30, 2015, respectively, and zero for each of the three and nine months ended September 30, 2014. See Note 2 and Note 9.
[8]	Represents expenses incurred on and subsequent to the date of the acquisition of the Partnership assets, as well as expenses incurred by Anadarko on a historical basis related to the Partnership assets prior to the acquisition of such assets.
[9]	Represents general and administrative expense incurred on and subsequent to the date of the Partnership’s acquisition of the Partnership assets, as well as a management services fee for reimbursement of expenses incurred by Anadarko for periods prior to the acquisition of the Partnership assets by the Partnership. These amounts include equity-based compensation expense allocated to the Partnership by Anadarko (see WES LTIP and WGP LTIP and Anadarko Incentive Plans within this Note 5).
[10]	For the three and nine months ended September 30, 2015, includes accretion expense recognized on the Deferred purchase price obligation - Anadarko for the acquisition of DBJV (see Note 2 and Note 9).
[11]	Represents distributions paid under the partnership agreement (see Note 3 and Note 4).

Transactions with Affiliates 47

Transactions with Affiliates - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	May. 31, 2008	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015		Sep. 30, 2014	Dec. 31, 2014
Related Party Transaction [Line Items]
Note receivable - Anadarko		$ 260,000,000		$ 260,000,000			$ 260,000,000	[1]
Above-market component of swap extensions with Anadarko		7,916,000		7,916,000	[2]
Contributions of equity-based compensation from Anadarko				$ 2,679,000
Western Gas Partners Long Term Incentive Plan [Member]
Related Party Transaction [Line Items]
Units vesting period				3 years
Equity-based compensation expense		100,000	$ 200,000	$ 400,000		$ 500,000
Western Gas Equity Partners Long Term Incentive Plan [Member] | Anadarko Incentive Plans [Member]
Related Party Transaction [Line Items]
Equity-based compensation expense		$ 1,000,000	$ 900,000	3,100,000		$ 2,700,000
Contributions of equity-based compensation from Anadarko				$ 2,700,000
Gathering, Treating and Transportation [Member]
Related Party Transaction [Line Items]
Affiliate throughput percent		42.00%	48.00%	46.00%		49.00%
Processing [Member]
Related Party Transaction [Line Items]
Affiliate throughput percent		47.00%	58.00%	51.00%		58.00%
Affiliates [Member]
Related Party Transaction [Line Items]
Note receivable - Anadarko	$ 260,000,000
Note receivable, due date	May 14, 2038
Fixed annual rate for note receivable bearing interest	6.50%
Affiliates [Member] | Level 2 inputs [Member] | Market approach valuation technique [Member]
Related Party Transaction [Line Items]
Fair value of the note receivable		$ 288,900,000		$ 288,900,000			$ 317,800,000
Independent Director [Member] | Western Gas Partners Long Term Incentive Plan [Member]
Related Party Transaction [Line Items]
Units vesting period				1 year
[1]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.
[2]	See Note 5.

Property, Plant and Equipment -

Property, Plant and Equipment - Historical Cost Table (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 5,862,721	$ 5,626,650	[1]
Accumulated depreciation	1,072,799	1,055,207	[1]
Net property, plant and equipment	4,789,922	4,571,443	[1]
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	3,191	2,884
Gathering Systems [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 5,431,716	4,972,892
Gathering Systems [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Gathering Systems [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	47 years
Pipelines And Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 136,303	151,107
Pipelines And Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	15 years
Pipelines And Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	45 years
Assets Under Construction [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 272,445	483,347
Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 19,066	$ 16,420
Other [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Other [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	40 years
[1]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.

Property, Plant and Equipment49

Property, Plant and Equipment - Additional Information (Details) $ in Millions	9 Months Ended
	Sep. 30, 2015USD ($)
Property, Plant and Equipment [Abstract]
Impairment	$ 11.8

Equity Investments - Equity Inv

Equity Investments - Equity Investments Table (Details) - USD ($) $ in Thousands		3 Months Ended			9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	[4]	Sep. 30, 2015		Sep. 30, 2014	[4]
Schedule of Equity Method Investments [Line Items]
Balance	[1]				$ 634,492
Investment earnings (loss), net of amortization	[2],[3]	$ 21,976	$ 19,063		59,137	[5]	$ 41,322	[5]
Contributions					9,052		63,267
Distributions	[5]				(60,645)		(43,061)
Distributions in excess of cumulative earnings	[5]				(12,409)	[6]	$ (14,387)
Balance		629,627			629,627
Fort Union [Member]
Schedule of Equity Method Investments [Line Items]
Balance					25,933
Investment earnings (loss), net of amortization					4,831
Contributions					0
Distributions					(4,606)
Distributions in excess of cumulative earnings	[6]				0
Balance		26,158			26,158
White Cliffs [Member]
Schedule of Equity Method Investments [Line Items]
Balance					44,315
Investment earnings (loss), net of amortization					10,663
Contributions					6,081
Distributions					(10,227)
Distributions in excess of cumulative earnings	[6]				(2,584)
Balance		48,248			48,248
Rendezvous [Member]
Schedule of Equity Method Investments [Line Items]
Balance					56,336
Investment earnings (loss), net of amortization					1,591
Contributions					0
Distributions					(3,047)
Distributions in excess of cumulative earnings	[6]				(2,708)
Balance		52,172			52,172
Mont Belvieu JV [Member]
Schedule of Equity Method Investments [Line Items]
Balance					121,337
Investment earnings (loss), net of amortization					17,256
Contributions					(432)
Distributions					(17,924)
Distributions in excess of cumulative earnings	[6]				(1,987)
Balance		118,250			118,250
Texas Express Gathering LLC [Member]
Schedule of Equity Method Investments [Line Items]
Balance					16,790
Investment earnings (loss), net of amortization					475
Contributions					0
Distributions					(685)
Distributions in excess of cumulative earnings	[6]				(82)
Balance		16,498			16,498
Texas Express Pipeline LLC [Member]
Schedule of Equity Method Investments [Line Items]
Balance					198,793
Investment earnings (loss), net of amortization					11,691
Contributions					1,520
Distributions					(11,880)
Distributions in excess of cumulative earnings	[6]				(4,302)
Balance		195,822			195,822
Front Range Pipeline LLC [Member]
Schedule of Equity Method Investments [Line Items]
Balance					170,988
Investment earnings (loss), net of amortization					12,630
Contributions					1,883
Distributions					(12,276)
Distributions in excess of cumulative earnings	[6]				(746)
Balance		$ 172,479			$ 172,479
[1]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.
[2]	Income earned from equity investments is classified as affiliate. See Note 1.
[3]	Represents amounts earned or incurred on and subsequent to the date of acquisition of the Partnership assets, as well as amounts earned or incurred by Anadarko on a historical basis related to the Partnership assets prior to the acquisition of such assets, recognized under gathering, treating or processing agreements, and purchase and sale agreements.
[4]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.
[5]	Income earned on, distributions from and contributions to equity investments are classified as affiliate. See Note 1.
[6]	Distributions in excess of cumulative earnings, classified as investing cash flows in the consolidated statements of cash flows, is calculated on an individual investment basis.

Components of Working Capital -

Components of Working Capital - Other Current Assets Table (Details) - USD ($) $ in Thousands		Sep. 30, 2015	Dec. 31, 2014
Other Current Assets [Line Items]
Natural gas liquids inventory		$ 6,486	$ 5,316
Natural gas imbalance receivables		177	415
Prepaid insurance		2,591	2,443
Other		2,145	1,893
Total other current assets	[1]	$ 11,399	$ 10,067	[2]
[1]	Other current assets includes natural gas imbalance receivables from affiliates of zero and $0.2 million as of September 30, 2015, and December 31, 2014, respectively.
[2]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.

Components of Working Capital52

Components of Working Capital - Accrued Liabilities Table (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Accrued Liabilities [Line Items]
Accrued interest expense	$ 34,169	$ 24,741
Short-term asset retirement obligations	4,335	1,224
Short-term remediation and reclamation obligations	475	475
Income taxes payable	701	207
Total accrued liabilities	138,812	170,789	[1]
Accrued Capital Expenditures [Member]
Accrued Liabilities [Line Items]
Other accrued liabilities	70,118	128,856
Accrued Plant Purchases [Member]
Accrued Liabilities [Line Items]
Other accrued liabilities	26,068	14,023
Other Accrued Liabilities [Member]
Accrued Liabilities [Line Items]
Other accrued liabilities	$ 2,946	$ 1,263
[1]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.

Debt and Interest Expense - Deb

Debt and Interest Expense - Debt Outstanding Table (Details) - USD ($)		Sep. 30, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Total long-term debt principal		$ 2,600,000,000	$ 2,430,000,000
Carrying value		2,587,189,000	2,422,954,000	[1]
Market approach valuation technique [Member] | Level 2 inputs [Member]
Debt Instrument [Line Items]
Fair value	[2]	2,550,312,000	2,511,253,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Principal		180,000,000	510,000,000
Carrying value		180,000,000	510,000,000
Revolving Credit Facility [Member] | Market approach valuation technique [Member] | Level 2 inputs [Member]
Debt Instrument [Line Items]
Fair value	[2]	180,000,000	510,000,000
Senior Notes [Member] | 5.375% Senior Notes due 2021 [Member]
Debt Instrument [Line Items]
Principal		500,000,000	500,000,000
Carrying value		496,139,000	495,714,000
Senior Notes [Member] | 5.375% Senior Notes due 2021 [Member] | Market approach valuation technique [Member] | Level 2 inputs [Member]
Debt Instrument [Line Items]
Fair value	[2]	534,860,000	549,530,000
Senior Notes [Member] | 4.000% Senior Notes due 2022 [Member]
Debt Instrument [Line Items]
Principal		670,000,000	670,000,000
Carrying value		672,662,000	672,930,000
Senior Notes [Member] | 4.000% Senior Notes due 2022 [Member] | Market approach valuation technique [Member] | Level 2 inputs [Member]
Debt Instrument [Line Items]
Fair value	[2]	654,858,000	681,942,000
Senior Notes [Member] | 2.600% Senior Notes due 2018 [Member]
Debt Instrument [Line Items]
Principal		350,000,000	350,000,000
Carrying value		350,380,000	350,474,000
Senior Notes [Member] | 2.600% Senior Notes due 2018 [Member] | Market approach valuation technique [Member] | Level 2 inputs [Member]
Debt Instrument [Line Items]
Fair value	[2]	350,151,000	352,162,000
Senior Notes [Member] | 5.450% Senior Notes due 2044 [Member]
Debt Instrument [Line Items]
Principal		400,000,000	400,000,000
Carrying value		393,901,000	393,836,000
Senior Notes [Member] | 5.450% Senior Notes due 2044 [Member] | Market approach valuation technique [Member] | Level 2 inputs [Member]
Debt Instrument [Line Items]
Fair value	[2]	365,196,000	417,619,000
Senior Notes [Member] | 3.950% Senior Notes due 2025 [Member]
Debt Instrument [Line Items]
Principal		500,000,000	0
Carrying value		494,107,000	0
Senior Notes [Member] | 3.950% Senior Notes due 2025 [Member] | Market approach valuation technique [Member] | Level 2 inputs [Member]
Debt Instrument [Line Items]
Fair value	[2]	$ 465,247,000	$ 0
[1]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.
[2]	Fair value is measured using the market approach and Level 2 inputs.

Debt and Interest Expense - D54

Debt and Interest Expense - Debt Activity Table (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)
Debt Instrument [Line Items]
Beginning balance	$ 2,422,954	[1]
Other	(5,765)
Ending balance	2,587,189
Senior Notes [Member] | 3.950% Senior Notes due 2025 [Member]
Debt Instrument [Line Items]
Beginning balance	0
Issuance of Senior Notes	500,000
Ending balance	494,107
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Beginning balance	510,000
Borrowings	280,000
Repayments	(610,000)
Ending balance	$ 180,000
[1]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.

Debt and Interest Expense - Int

Debt and Interest Expense - Interest Expense Table (Details) - USD ($) $ in Thousands		3 Months Ended			9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014		Sep. 30, 2015	Sep. 30, 2014
Debt Instrument [Line Items]
Interest expense	[1]	$ 31,773	$ 20,878	[2]	$ 82,337	$ 55,703	[2]
Third Parties [Member]
Debt Instrument [Line Items]
Long-term debt		26,972	21,671		75,047	59,251
Amortization of debt issuance costs and commitment fees		1,530	1,107		4,196	3,799
Capitalized interest		(1,039)	(1,900)		(6,826)	(7,347)
Interest expense		27,463	20,878		72,417	55,703
Affiliates [Member]
Debt Instrument [Line Items]
Interest expense	[3]	4,310	0		9,920	0
Affiliates [Member] | Deferred Purchase Price Obligation - Anadarko [Member]
Debt Instrument [Line Items]
Interest expense, related party	[4]	$ 4,310	$ 0		$ 9,920	$ 0
[1]	Includes affiliate (as defined in Note 1) interest expense of $4.3 million and $9.9 million for the three and nine months ended September 30, 2015, respectively, and zero for each of the three and nine months ended September 30, 2014. See Note 2 and Note 9.
[2]	Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.
[3]	For the three and nine months ended September 30, 2015, includes accretion expense recognized on the Deferred purchase price obligation - Anadarko for the acquisition of DBJV (see Note 2 and Note 9).
[4]	See Note 2 for a discussion of the accretion and present value of the Deferred purchase price obligation - Anadarko.

Debt and Interest Expense - Add

Debt and Interest Expense - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2015
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility, interest rate at period end	1.49%	1.46%
Facility, fee rate	0.20%	0.20%
Facility, outstanding borrowings	$ 180,000,000
Outstanding letters of credit	12,800,000
Facility, available borrowing capacity	$ 1,000,000,000
Facility, expiration date	Feb. 26, 2019
Senior Notes [Member] | 5.375% Senior Notes due 2021 [Member]
Debt Instrument [Line Items]
Fixed interest rate	5.375%
Debt instrument, maturity date	Jun. 1, 2021
Senior Notes [Member] | 4.000% Senior Notes due 2022 [Member]
Debt Instrument [Line Items]
Fixed interest rate	4.00%
Debt instrument, maturity date	Jul. 1, 2022
Senior Notes [Member] | 2.600% Senior Notes due 2018 [Member]
Debt Instrument [Line Items]
Fixed interest rate	2.60%
Debt instrument, maturity date	Aug. 15, 2018
Senior Notes [Member] | 5.450% Senior Notes due 2044 [Member]
Debt Instrument [Line Items]
Fixed interest rate	5.45%
Debt instrument, maturity date	Apr. 1, 2044
Senior Notes [Member] | 3.950% Senior Notes due 2025 [Member]
Debt Instrument [Line Items]
Fixed interest rate	3.95%
Offering percent			98.789%
Effective interest rate	4.205%
Underwriting discount	$ 3,300,000
Debt instrument, maturity date	Jun. 1, 2025

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]
Committed capital	$ 42		$ 42
Rent expense associated with office, warehouse and equipment leases	$ 4.9	$ 2.4	$ 13.6	$ 6.8