Western Midstream Partners 10-Q 6 Aug 14 2014 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Jun. 30, 2014	Aug. 04, 2014
Document And Entity Information [Abstract]	'	'
Entity Registrant Name	'WESTERN GAS PARTNERS LP	'
Entity Central Index Key	'0001414475	'
Document Type	'10-Q	'
Document Period End Date	30-Jun-14	'
Amendment Flag	'false	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q2	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock Shares Outstanding	'	119,070,104

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	3 Months Ended				6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Revenues	'		'		'		'
Total revenues	$329,944		$251,402	[1]	$609,401		$477,168	[1]
Equity income, net	13,008	[2]	3,456	[1],[2]	22,259	[2],[3]	7,424	[1],[2],[3]
Operating expenses	'		'		'		'
Cost of product	118,085	[4]	93,460	[1],[4]	210,035	[4]	176,543	[1],[4]
Operation and maintenance	50,875	[4]	41,669	[1],[4]	91,407	[4]	78,408	[1],[4]
General and administrative	8,000	[4]	7,288	[1],[4]	16,415	[4]	14,952	[1],[4]
Property and other taxes	7,113		6,086	[1]	14,154		11,871	[1]
Depreciation, amortization and impairments	43,746		36,496	[1]	84,358		68,936	[1]
Total operating expenses	227,819		184,999	[1]	416,369		350,710	[1]
Operating income	115,133		69,859	[1]	215,291		133,882	[1]
Interest income, net - affiliates	4,225	[5]	4,225	[1],[5]	8,450	[5]	8,450	[1],[5]
Interest expense	-20,864		-12,654	[1]	-34,825		-24,465	[1]
Other income, net	214		499	[1]	691		1,173	[1]
Income before income taxes	98,708		61,929	[1]	189,607		119,040	[1]
Income tax (benefit) expense	226		53	[1]	-2		4,219	[1]
Net income	98,482		61,876	[1]	189,609		114,821	[1]
Net income attributable to noncontrolling interest	3,450		1,860	[1]	7,142		4,091	[1]
Net income attributable to Western Gas Partners, LP	95,032		60,016	[1]	182,467		110,730	[1]
Limited partners' interest in net income:	'		'		'		'
Pre-acquisition net (income) loss allocated to Anadarko	0		948	[1]	956		-4,510	[1]
General partner interest in net (income) loss	-28,047	[6]	-16,154	[1],[6]	-52,881	[6]	-29,040	[1],[6]
Limited partners' interest in net income	66,985	[6]	44,810	[1],[6]	130,542	[6]	77,180	[1],[6]
Affiliated Entity [Member]	'		'		'		'
Revenues	'		'		'		'
Gathering, processing and transportation of natural gas and natural gas liquids	98,973		69,175	[1]	184,134		135,074	[1]
Natural gas, natural gas liquids and condensate sales	156,851		129,996	[1]	277,251		241,666	[1]
Other, net	842		1,145	[1]	1,571		1,145	[1]
Total revenues	256,666	[7]	200,316	[1],[7]	462,956	[7]	377,885	[1],[7]
Operating expenses	'		'		'		'
Cost of product	35,230	[7]	32,119	[7]	51,864	[7]	64,048	[7]
Operation and maintenance	16,817	[8]	14,186	[8]	27,916	[8]	27,552	[8]
General and administrative	6,479	[9]	5,589	[9]	13,293	[9]	11,458	[9]
Total operating expenses	58,526		51,894		93,073		103,058
Third Parties [Member]	'		'		'		'
Revenues	'		'		'		'
Gathering, processing and transportation of natural gas and natural gas liquids	62,277		40,625	[1]	118,565		77,616	[1]
Natural gas, natural gas liquids and condensate sales	9,803		9,565	[1]	25,841		19,624	[1]
Other, net	1,198		896	[1]	2,039		2,043	[1]
Total revenues	$73,278		$51,086	[1]	$146,445		$99,283	[1]
Limited Partner [Member] | Common Units [Member]	'		'		'		'
Limited partners' interest in net income:	'		'		'		'
Net income per common unit - basic and diluted	$0.57		$0.41	[1]	$1.11		$0.72	[1]
Weighted average common units outstanding - basic and diluted	118,177		108,736	[1]	117,948		106,784	[1]
[1]	Financial information has been recast to include the financial position and results attributable to the TEFR Interests. 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]	Cost of product includes product purchases from Anadarko (as defined in Note 1) of $35.2 million and $51.9 million for the three and six months ended June 30, 2014, respectively, and $32.1 million and $64.0 million for the three and six months ended June 30, 2013, respectively. Operation and maintenance includes charges from Anadarko of $16.8 million and $27.9 million for the three and six months ended June 30, 2014, respectively, and $14.2 million and $27.6 million for the three and six months ended June 30, 2013, respectively. General and administrative includes charges from Anadarko of $6.5 million and $13.3 million for the three and six months ended June 30, 2014, respectively, and $5.6 million and $11.5 million for the three and six months ended June 30, 2013, respectively. See Note 5
[5]	Represents interest income recognized on the note receivable from Anadarko.
[6]	Represents net income earned on and subsequent to the date of acquisition of the Partnership assets (as defined in Note 1). See Note 4
[7]	Represents amounts earned on and subsequent to the date of acquisition of the Partnership assets, as well as amounts earned 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.
[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 the Partnership assets by the Partnership.
[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).

Consolidated_Statements_of_Inc1

Consolidated Statements of Income (Parenthetical) (USD $)	3 Months Ended				6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Cost of product	$118,085	[1]	$93,460	[1],[2]	$210,035	[1]	$176,543	[1],[2]
Operation and maintenance	50,875	[1]	41,669	[1],[2]	91,407	[1]	78,408	[1],[2]
General and administrative	8,000	[1]	7,288	[1],[2]	16,415	[1]	14,952	[1],[2]
Affiliated Entity [Member]	'		'		'		'
Cost of product	35,230	[3]	32,119	[3]	51,864	[3]	64,048	[3]
Operation and maintenance	16,817	[4]	14,186	[4]	27,916	[4]	27,552	[4]
General and administrative	$6,479	[5]	$5,589	[5]	$13,293	[5]	$11,458	[5]
[1]	Cost of product includes product purchases from Anadarko (as defined in Note 1) of $35.2 million and $51.9 million for the three and six months ended June 30, 2014, respectively, and $32.1 million and $64.0 million for the three and six months ended June 30, 2013, respectively. Operation and maintenance includes charges from Anadarko of $16.8 million and $27.9 million for the three and six months ended June 30, 2014, respectively, and $14.2 million and $27.6 million for the three and six months ended June 30, 2013, respectively. General and administrative includes charges from Anadarko of $6.5 million and $13.3 million for the three and six months ended June 30, 2014, respectively, and $5.6 million and $11.5 million for the three and six months ended June 30, 2013, respectively. See Note 5
[2]	Financial information has been recast to include the financial position and results attributable to the TEFR Interests. See Note 1 and Note 2.
[3]	Represents amounts earned on and subsequent to the date of acquisition of the Partnership assets, as well as amounts earned 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]	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 the Partnership assets by the Partnership.
[5]	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).

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Jun. 30, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets	'		'
Cash and cash equivalents	$110,629		$100,728	[1]
Accounts receivable, net	109,014	[2]	84,060	[1],[2]
Other current assets	4,560	[3]	10,022	[1],[3]
Total current assets	224,203		194,810	[1]
Note receivable - Anadarko	260,000		260,000	[1]
Property, plant and equipment	'		'
Cost	4,591,935		4,239,100	[1]
Less accumulated depreciation	936,568		855,845	[1]
Net property, plant and equipment	3,655,367		3,383,255	[1]
Goodwill	105,336		105,336	[1]
Other intangible assets	52,909		53,606	[1]
Equity investments	637,478		593,400	[1]
Other assets	29,519		27,401	[1]
Total assets	4,964,812		4,617,808	[1]
Current liabilities	'		'
Accounts and natural gas imbalance payables	28,640	[4]	39,589	[1],[4]
Accrued ad valorem taxes	14,539		13,860	[1]
Income taxes payable	410		0	[1]
Accrued liabilities	133,069	[5]	137,011	[1],[5]
Total current liabilities	176,658		190,460	[1]
Long-term debt	2,022,876		1,418,169	[1]
Deferred income taxes	601		37,998	[1]
Asset retirement obligations and other	81,927		79,145	[1]
Total long-term liabilities	2,105,404		1,535,312	[1]
Total liabilities	2,282,062		1,725,772	[1]
Equity and partners' capital	'		'
Common units (118,971,307 and 117,322,812 units issued and outstanding at June 30, 2014, and December 31, 2013, respectively)	2,528,069		2,431,193	[1]
General partner units (2,408,699 and 2,394,345 units issued and outstanding at June 30, 2014, and December 31, 2013, respectively)	84,894		78,157	[1]
Net investment by Anadarko	0		312,092	[1]
Total partners' capital	2,612,963		2,821,442	[1]
Noncontrolling interest	69,787		70,594	[1]
Total equity and partners' capital	2,682,750		2,892,036	[1]
Total liabilities, equity and partners' capital	$4,964,812		$4,617,808	[1]
[1]	Financial information has been recast to include the financial position and results attributable to the TEFR Interests. See Note 1 and Note 2.
[2]	Accounts receivable, net includes amounts receivable from affiliates (as defined in Note 1) of $69.8 million and $47.9 million as of June 30, 2014, and December 31, 2013, respectively.
[3]	Other current assets includes natural gas imbalance receivables from affiliates of $0.2 million and $0.1 million as of June 30, 2014, and December 31, 2013, respectively.
[4]	Accounts and natural gas imbalance payables includes amounts payable to affiliates of $0.1 million and $2.3 million as of June 30, 2014, and December 31, 2013, respectively.
[5]	Accrued liabilities includes amounts payable to affiliates of zero and $0.1 million as of June 30, 2014, and December 31, 2013, respectively.

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2014		Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Common units issued	118,971,307		117,322,812
Common units outstanding	118,971,307		117,322,812
General partner units issued	2,408,699		2,394,345
General partner units outstanding	2,408,699		2,394,345
Accounts receivable, net	$109,014	[1]	$84,060	[1],[2]
Other current assets	4,560	[3]	10,022	[2],[3]
Accounts and natural gas imbalance payables	28,640	[4]	39,589	[2],[4]
Accrued liabilities	133,069	[5]	137,011	[2],[5]
Affiliated Entity [Member]	'		'
Accounts receivable, net	69,800		47,900
Other current assets	200		100
Accounts and natural gas imbalance payables	100		2,300
Accrued liabilities	$0		$100
[1]	Accounts receivable, net includes amounts receivable from affiliates (as defined in Note 1) of $69.8 million and $47.9 million as of June 30, 2014, and December 31, 2013, respectively.
[2]	Financial information has been recast to include the financial position and results attributable to the TEFR Interests. See Note 1 and Note 2.
[3]	Other current assets includes natural gas imbalance receivables from affiliates of $0.2 million and $0.1 million as of June 30, 2014, and December 31, 2013, respectively.
[4]	Accounts and natural gas imbalance payables includes amounts payable to affiliates of $0.1 million and $2.3 million as of June 30, 2014, and December 31, 2013, respectively.
[5]	Accrued liabilities includes amounts payable to affiliates of zero and $0.1 million as of June 30, 2014, and December 31, 2013, respectively.

Consolidated_Statement_of_Equi

Consolidated Statement of Equity and Partners' Capital (USD $)		Total	Net Investment by Anadarko [Member]	Common Units [Member]	General Partner Units [Member]	Noncontrolling Interest [Member]
In Thousands
Balance at Dec. 31, 2013	[1]	$2,892,036	$312,092	$2,431,193	$78,157	$70,594
Net income (loss)		189,609	-956	130,542	52,881	7,142
Issuance of common and general partner units, net of offering expenses		92,827	'	91,929	898	'
Distributions to noncontrolling interest owner		-7,949	'	'	'	-7,949
Distributions to unitholders		-191,359	'	-144,281	-47,078	'
Acquisitions from affiliates		-356,250	-372,784	16,534	'	'
Contributions of equity-based compensation from Anadarko		1,733	'	1,698	35	'
Net pre-acquisition contributions from Anadarko		23,788	23,788	'	'	'
Net contributions from Anadarko of other assets		43	'	42	1	'
Elimination of net deferred tax liabilities		38,160	38,160	'	'	'
Other		112	-300	412	'	'
Balance at Jun. 30, 2014		$2,682,750	$0	$2,528,069	$84,894	$69,787
[1]	Financial information has been recast to include the financial position and results attributable to the TEFR Interests. See Note 1 and Note 2.

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014		Jun. 30, 2013
Cash flows from operating activities	'		'
Net income	$189,609		$114,821	[1]
Adjustments to reconcile net income to net cash provided by operating activities:	'		'
Depreciation, amortization and impairments	84,358		68,936	[1]
Non-cash equity-based compensation expense	2,187		1,682	[1]
Deferred income taxes	463		19,355	[1]
Debt-related amortization and other items, net	1,358		1,126	[1]
Equity income, net	-22,259	[2],[3]	-7,424	[1],[2],[3]
Distributions from equity investment earnings	26,793	[2]	11,032	[1],[2]
Changes in assets and liabilities:	'		'
(Increase) decrease in accounts receivable, net	-23,353		-26,807	[1]
Increase (decrease) in accounts and natural gas imbalance payables and accrued liabilities, net	794		336	[1]
Change in other items, net	4,247		235	[1]
Net cash provided by operating activities	264,197		183,292	[1]
Cash flows from investing activities	'		'
Capital expenditures	-359,752		-339,756	[1]
Contributions in aid of construction costs from affiliates	182		0	[1]
Acquisitions	-360,952		-679,610	[1]
Investments in equity affiliates	-59,245		-156,217	[1]
Distributions from equity investments in excess of cumulative earnings	9,848	[2],[4]	0	[1],[2]
Proceeds from the sale of assets to affiliates	0		96	[1]
Capitalized interest on equity investments	-857		-7,195	[1]
Net cash used in investing activities	-770,776		-1,182,682	[1]
Cash flows from financing activities	'		'
Borrowings, net of debt issuance costs	1,076,895		494,948	[1]
Repayments of debt	-480,000		-245,000	[1]
Increase (decrease) in outstanding checks	2,517		-1,809	[1]
Proceeds from the issuance of common and general partner units, net of offering expenses	92,588		425,386	[1]
Distributions to unitholders	-191,359		-135,801	[1]
Contributions from noncontrolling interest owner	0		1,097	[1]
Distributions to noncontrolling interest owner	-7,949		-4,660	[1]
Net contributions from Anadarko	23,788		119,428
Net cash provided by financing activities	516,480		653,589	[1]
Net increase (decrease) in cash and cash equivalents	9,901		-345,801	[1]
Cash and cash equivalents at beginning of period	100,728	[1]	419,981	[1]
Cash and cash equivalents at end of period	110,629		74,180	[1]
Supplemental disclosures	'		'
Net contributions from Anadarko of other assets	-43		'
Net distributions to Anadarko of other assets	'		615	[1]
Interest paid, net of capitalized interest	26,346		23,516	[1]
Taxes paid (reimbursements received)	-340		0	[1]
Capital lease asset transfer	4,833	[5]	0	[1],[5]
Affiliated Entity [Member]	'		'
Cash flows from investing activities	'		'
Contributions in aid of construction costs from affiliates	182		0	[1]
Acquisitions	-360,952		-466,936	[1]
Proceeds from the sale of assets to affiliates	0		82	[1]
Third Parties [Member]	'		'
Cash flows from investing activities	'		'
Acquisitions	0		-212,674	[1]
Proceeds from the sale of assets to affiliates	$0		$14	[1]
[1]	Financial information has been recast to include the financial position and results attributable to the TEFR Interests. See Note 1 and Note 2.
[2]	Income earned on, distributions from and contributions to equity investments are classified as affiliate. See Note 1.
[3]	Income earned from equity investments is classified as affiliate. See Note 1.
[4]	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.
[5]	For the six months ended June 30, 2014, represents transfers of $0.2 million and $4.6 million from other current assets and other long-term assets, respectively, associated with the capital lease components of a processing agreement. See Note 6.

Consolidated_Statements_of_Cas1

Consolidated Statements of Cash Flows Consolidated Statements of Cash Flows (Parenthetical) (Details) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014
Capital lease asset transfer	$4,833	[1]
Other Current Assets [Member]	'
Capital lease asset transfer	200	[1]
Other Noncurrent Assets [Member]	'
Capital lease asset transfer	$4,600	[1]
[1]	For the six months ended June 30, 2014, represents transfers of $0.2 million and $4.6 million from other current assets and other long-term assets, respectively, associated with the capital lease components of a processing agreement. See Note 6.

Description_of_Business_and_Ba

Description of Business and Basis of Presentation	6 Months Ended
	Jun. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [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 own, operate, acquire and develop 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”) (see Note 2). The interests in TEP, TEG and FRP are referred to collectively as the “TEFR Interests.” All income earned on, distributions from and contributions to the Partnership’s equity investments are considered to be affiliate transactions. “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 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 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 June 30, 2014, the Partnership’s assets and investments accounted for under the equity method consisted of the following:
			Owned and		Operated			Non-Operated			Equity Interests
			Operated		Interests			Interests
	Natural gas gathering systems		13		1			5			2
	NGL gathering systems		—		—			—			2
	Natural gas treating facilities		8		—			—			1
	Natural gas processing facilities		9		3			—			2
	NGL pipelines		3		—			—			2
	Natural gas pipelines		3		—			—			—
	Oil pipeline		—		—			—			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. The Partnership completed construction of Train I at the Lancaster processing plant (located in the DJ Basin complex) in Northeast Colorado in April 2014, and is constructing Train II at the same plant with operations expected to commence in the second quarter of 2015.
	Western Gas Equity Partners, LP. WGP owns the following types of interests in the Partnership: (i) the 2.0% 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 its partnership interests in the Partnership.
	1.  DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (CONTINUED)
	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 and Anadarko-Operated Marcellus Interest (see Note 2) and its 50% share of the assets, liabilities, revenues and expenses attributable to the Newcastle system in the accompanying consolidated financial statements.
	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 under the particular circumstances. 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.
	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 2013 Form 10-K, as filed with the SEC on February 28, 2014. Management believes that the disclosures made are adequate to make the information not misleading.
	Presentation of Partnership assets. The “Partnership assets” refer collectively to the assets owned and interests accounted for under the equity method by the Partnership as of June 30, 2014. Because Anadarko controls the Partnership through its ownership and control of WGP, which owns the Partnership’s general partner, each acquisition of the 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 the Partnership assets as of 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 for purposes of calculating net income per common unit.
	1.  DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (CONTINUED)
	Equity investments. The following table presents the activity in the Partnership’s equity investments in Fort Union, White Cliffs, Rendezvous, the Mont Belvieu JV, TEG, TEP and FRP for the six months ended June 30, 2014:
		Equity Investments
	thousands	Fort			White				Rendezvous			Mont			TEG			TEP			FRP			Total
		Union			Cliffs							Belvieu JV
	Balance at December 31, 2013	$	25,172		$	35,039			$	60,928		$	122,480		$	16,649		$	197,731		$	135,401		$	593,400
	Investment earnings (loss), net of amortization	3,199			4,906				687			14,713			317			(53		)	(1,510		)	22,259
	Contributions	—			10,000				—			3,956			352			5,773			37,522			57,603
	Capitalized interest	—			—				—			—			—			—			857			857
	Distributions	(3,637		)	(4,616		)		(1,658		)	(16,510		)	(372		)	—			—			(26,793		)
	Distributions in excess of cumulative earnings (1)	—			(885		)		(1,395		)	—			(338		)	(3,710		)	(3,520		)	(9,848		)
	Balance at June 30, 2014	$	24,734		$	44,444			$	58,562		$	124,639		$	16,608		$	199,741		$	168,750		$	637,478
	(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.
	Recently issued accounting standards. Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers, 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 to which the entity expects to be entitled in exchange for those goods or services. This ASU is effective for annual and interim periods beginning in 2017 and is required to be adopted using one of two retrospective application methods, with no early adoption permitted. The Partnership is currently evaluating the impact of the adoption of this ASU on its consolidated financial statements.
	ASU 2014-08, Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity, changes the criteria for reporting discontinued operations and requires additional disclosures, both for discontinued operations and for individually significant dispositions and assets classified as held for sale not qualifying as discontinued operations. This ASU is effective for annual and interim periods beginning in 2015, with early adoption permitted for disposals or for assets classified as held for sale that have not been reported in previously issued financial statements. The Partnership early adopted this ASU on a prospective basis beginning with the first quarter of 2014. The adoption did not have a material impact on the Partnership’s consolidated financial statements.
	ASU 2013-11, Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists, requires that an unrecognized tax benefit, or a portion of an unrecognized tax benefit, be presented in the financial statements as a reduction to a deferred tax asset, except in certain circumstances. This ASU is effective for annual and interim periods beginning in 2014. The Partnership adopted this ASU on a prospective basis beginning with the first quarter of 2014. The adoption did not have a material impact on the Partnership’s consolidated financial statements.

Acquisitions

Acquisitions	6 Months Ended
	Jun. 30, 2014
Business Combinations [Abstract]	'
Acquisitions	'
	2.  ACQUISITIONS
	The following table presents the acquisitions completed by the Partnership during 2014 and 2013, and identifies the funding sources for such acquisitions:
	thousands except unit and percent amounts		Acquisition		Percentage			Borrowings			Cash		Common
			Date		Acquired						On Hand		Units Issued
	Non-Operated Marcellus Interest (1)		3/1/13		33.75	%		$	250,000		$	215,500	449,129
	Anadarko-Operated Marcellus Interest (2)		3/8/13		33.75	%		133,500			—		—
	Mont Belvieu JV (3)		6/5/13		25	%		—			78,129		—
	OTTCO (4)		9/3/13		100	%		27,500			—		—
	TEFR Interests (5)		3/3/14		Various (5)			350,000			6,250		308,490
	(1)	The Partnership acquired Anadarko’s 33.75% interest (non-operated) in the Liberty and Rome gas gathering systems, serving production from the Marcellus shale in north-central Pennsylvania. The interest acquired is referred to as the “Non-Operated Marcellus Interest.” In connection with the issuance of the common units, the Partnership’s general partner purchased 9,166 general partner units for consideration of $0.5 million to maintain its 2.0% general partner interest in the Partnership.
	(2)	The Partnership acquired a 33.75% interest in each of the Larry’s Creek, Seely and Warrensville gas gathering systems, which are operated by Anadarko and serve production from the Marcellus shale in north-central Pennsylvania, from a third party. The interest acquired is referred to as the “Anadarko-Operated Marcellus Interest.” During the third quarter of 2013, the Partnership recorded a $1.1 million decrease in the assets acquired and liabilities assumed in the acquisition, representing the final purchase price allocation.
	(3)	The Partnership acquired a 25% interest in the Mont Belvieu JV, an entity formed to design, construct, and own two fractionation trains located in Mont Belvieu, Texas, from a third party. The interest acquired is accounted for under the equity method of accounting.
	(4)	The Partnership acquired Overland Trail Transmission, LLC (“OTTCO”), a Delaware limited liability company, from a third party. OTTCO owns and operates an intrastate pipeline that connects the Partnership’s Red Desert and Granger complexes in southwestern Wyoming.
	(5)	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 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’s general partner purchased 6,296 general partner units for consideration of $0.4 million to maintain its 2.0% general partner interest in the Partnership.
	TEFR Interests acquisition. Because the acquisition of the TEFR Interests 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 TEFR Interests as if the Partnership owned the TEFR Interests for all periods presented. The consolidated financial statements for periods prior to the Partnership’s acquisition of the TEFR Interests 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 TEFR Interests during the periods reported.
	2.  ACQUISITIONS (CONTINUED)
	The following table presents the impact of the TEFR Interests on revenue, equity income (loss), net and net income as presented in the Partnership’s historical consolidated statements of income:
			Three Months Ended June 30, 2013
	thousands		Partnership Historical				TEFR Interests			Combined
	Revenues		$	251,402			$	—		$	251,402
	Equity income (loss), net		3,724				(268		)	3,456
	Net income (loss)		$	62,060			$	(184	)	$	61,876
			Six Months Ended June 30, 2013
	thousands		Partnership Historical				TEFR Interests			Combined
	Revenues		$	477,168			$	—		$	477,168
	Equity income (loss), net		7,705				(281		)	7,424
	Net income (loss)		$	114,948			$	(127	)	$	114,821

Partnership_Distributions

Partnership Distributions	6 Months Ended
	Jun. 30, 2014
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 unitholders for the periods presented:
	thousands except per-unit amounts		Total Quarterly		Total Quarterly		Date of
	Quarters Ended		Distribution		Cash Distribution		Distribution
			per Unit
	2013
	31-Mar-13		$	0.54	$	70,143	May 2013
	30-Jun-13		$	0.56	$	79,315	Aug-13
	2014
	31-Mar-14		$	0.625	$	98,749	May 2014
	June 30, 2014 (1)		$	0.65	$	105,655	Aug-14
	(1)	On July 18, 2014, the board of directors of the Partnership’s general partner declared a cash distribution to the Partnership’s unitholders of $0.650 per unit, or $105.7 million in aggregate, including incentive distributions. The cash distribution is payable on August 13, 2014, to unitholders of record at the close of business on July 31, 2014.

Equity_and_Partners_Capital

Equity and Partners' Capital	6 Months Ended
	Jun. 30, 2014
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 2014 and 2013:
	thousands except unit	Common		GP Units		Price Per		Underwriting		Net
	and per-unit amounts	Units Issued		Issued (1)		Unit		Discount and		Proceeds
								Other Offering
								Expenses
	May 2013 equity offering (2)	7,015,000		143,163		$	61.18	$	13,203	$	424,733
	December 2013 equity offering (3)	4,800,000		97,959		61.51		9,447		291,827
	Continuous Offering Program - 2013 (4)	685,735		13,996		60.84		965		41,603
	Continuous Offering Program - 2014 (5)	1,034,587		1,824		73.24		1,565		74,343
	(1)	Represents general partner units issued to the general partner in exchange for the general partner’s proportionate capital contribution to maintain its 2.0% general partner interest in the Partnership.
	(2)	Includes the issuance of 915,000 common units pursuant to the full exercise of the underwriters’ over-allotment option granted in connection with the May 2013 equity offering.
	(3)	Includes the issuance of 300,000 common units on January 3, 2014, pursuant to the partial exercise of the underwriters’ over-allotment option granted in connection with the December 2013 equity offering. Net proceeds from this partial exercise (including the general partner’s proportionate capital contribution) were $18.1 million.
	(4)	Represents common and general partner units issued during the year ended December 31, 2013, 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 “Continuous Offering Program”). Gross proceeds generated (including the general partner’s proportionate capital contributions) were $42.6 million. The price per unit in the table above represents an average price for all issuances under the Continuous Offering Program during 2013.
	(5)	Represents common and general partner units issued during the three and six months ended June 30, 2014, under the Continuous Offering Program. Gross proceeds generated (including the general partner’s proportionate capital contributions) were $75.9 million. The price per unit in the table above represents an average price for all issuances under the Continuous Offering Program during the six months ended June 30, 2014. Does not include the issuance of 98,797 common units that were sold in June 2014, but settled in July 2014, or the issuance of 21,308 general partner units to the general partner in exchange for the general partner’s proportionate capital contribution to maintain its 2.0% general partner interest in the Partnership. As of June 30, 2014, the Partnership had used substantially all the capacity to issue units under this registration statement.
	Common 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 common and general partner units issued during the six months ended June 30, 2014:
			Common		General		Total
			Units		Partner Units
	Balance at December 31, 2013		117,322,812		2,394,345		119,717,157
	December 2013 equity offering		300,000		6,122		306,122
	Long-Term Incentive Plan awards		5,418		112		5,530
	TEFR Interests acquisition		308,490		6,296		314,786
	Continuous Offering Program		1,034,587		1,824		1,036,411
	Balance at June 30, 2014		118,971,307		2,408,699		121,380,006
	Holdings of Partnership equity. As of June 30, 2014, WGP held 49,296,205 common units, representing a 40.6% limited partner interest in the Partnership, and, through its ownership of the general partner, WGP indirectly held 2,408,699 general partner units, representing a 2.0% general partner interest in the Partnership, and 100% of the Partnership’s IDRs. As of June 30, 2014, other subsidiaries of Anadarko held 757,619 common units, representing a 0.6% limited partner interest in the Partnership. As of June 30, 2014, the public held 68,917,483 common units, representing a 56.8% limited partner interest in the Partnership.
	4.  EQUITY AND PARTNERS’ CAPITAL (CONTINUED)
	The Partnership’s net income earned on and subsequent to the date of the acquisition of the Partnership assets (as defined in Note 1) is allocated to the general partner and the limited partners consistent with actual cash distributions, including incentive distributions allocable to the general partner. Undistributed earnings (net income in excess of distributions) or undistributed losses (available cash in excess of net income) are then allocated to the general partner and the limited partners in accordance with their respective ownership percentages.
	Basic and diluted net income per common unit are calculated by dividing the limited partners’ interest in net income 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 during which they were outstanding.

Transactions_With_Affiliates

Transactions With Affiliates	6 Months Ended
	Jun. 30, 2014
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, condensate and NGLs to Anadarko. In addition, the Partnership purchases natural gas from an affiliate of Anadarko pursuant to gas purchase agreements. Operating 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. Anadarko charged or credited the Partnership interest at a variable rate on outstanding affiliate balances for the periods these balances remained outstanding. 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, and affiliate-based interest expense on current intercompany balances is not charged. Chipeta Processing LLC cash settles its transactions directly with third parties and Anadarko, as well as with the other subsidiaries of the Partnership.
	Note receivable from 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 $336.9 million and $296.7 million at June 30, 2014, and December 31, 2013, 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.
	Commodity price swap agreements. The Partnership has commodity price swap agreements with Anadarko to mitigate exposure to 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 Granger, Hilight, Hugoton, Newcastle and MGR assets, as well as the DJ Basin complex, with various expiration dates through December 2016. In December 2013, the Partnership extended the commodity price swap agreements for the Hilight and Newcastle assets through December 2014. 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.
	5.  TRANSACTIONS WITH AFFILIATES (CONTINUED)
	Below is a summary of the fixed price ranges on the Partnership’s outstanding commodity price swap agreements as of June 30, 2014:
	per barrel except natural gas		2014							2015							2016
	Ethane		$	18.36		−	$	30.53		$	18.41		−	$	23.41		$	23.11
	Propane		$	40.38		−	$	53.78		$	47.08		−	$	52.99		$	52.9
	Isobutane		$	61.24		−	$	75.13		$	62.09		−	$	74.02		$	73.89
	Normal butane		$	53.89		−	$	66.83		$	54.62		−	$	65.04		$	64.93
	Natural gasoline		$	71.85		−	$	90.89		$	72.88		−	$	81.82		$	81.68
	Condensate		$	75.22		−	$	87.3		$	76.47		−	$	81.82		$	81.68
	Natural gas (per MMBtu)		$	3.45		−	$	6.2		$	4.66		−	$	5.96		$	4.87
	The following table summarizes realized gains and losses on commodity price swap agreements:
			Three Months Ended							Six Months Ended
			June 30,							June 30,
	thousands		2014				2013			2014				2013
	Gains (losses) on commodity price swap agreements related to sales: (1)
	Natural gas sales		$	2,013			$	2,404		$	(1,654	)		$	7,784
	Natural gas liquids sales		34,554				34,203			44,009				55,508
	Total		36,567				36,607			42,355				63,292
	Losses on commodity price swap agreements related to purchases (2)		(18,529		)		(22,857		)	(18,548		)		(42,711		)
	Net gains (losses) on commodity price swap agreements		$	18,038			$	13,750		$	23,807			$	20,581
	(1)	Reported in affiliate natural gas, natural gas liquids and 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.
	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, transportation and treating throughput (excluding equity investment throughput and throughput measured in barrels) attributable to natural gas production owned or controlled by Anadarko was 49% and 56% for the three months ended June 30, 2014 and 2013, respectively, and 49% and 57% for the six months ended June 30, 2014 and 2013, 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 58% and 57% for the three months ended June 30, 2014 and 2013, respectively, and 58% for each of the six months ended June 30, 2014 and 2013.
	Equipment purchases and sales. The following table summarizes the Partnership’s purchases from and sales to Anadarko of pipe and equipment:
			Six Months Ended June 30,
			2014				2013			2014				2013
	thousands		Purchases							Sales
	Cash consideration		$	4,702			$	1,436		$	—			$	82
	Net carrying value		4,745				773			—				34
	Partners’ capital adjustment		$	(43	)		$	663		$	—			$	48
	5.  TRANSACTIONS WITH AFFILIATES (CONTINUED)
	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 and its Chief Executive Officer. 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 $0.2 million for each of the three months ended June 30, 2014 and 2013 and $0.3 million for each of the six months ended June 30, 2014 and 2013.
	WGP LTIP and Anadarko Incentive Plans. The Partnership’s general and administrative expenses included $0.9 million and $1.8 million for the three and six months ended June 30, 2014, respectively, and $0.7 million and $1.4 million for the three and six months ended June 30, 2013, 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 Anadarko Incentive Plans. Of this amount, $1.7 million is reflected as a contribution to partners’ capital in the Partnership’s consolidated statement of equity and partners’ capital for the six months ended June 30, 2014.
	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							Six Months Ended
			June 30,							June 30,
	thousands		2014				2013			2014				2013
	Revenues (1)		$	256,666			$	200,316		$	462,956			$	377,885
	Equity income, net		13,008				3,456			22,259				7,424
	Cost of product (1)		35,230				32,119			51,864				64,048
	Operation and maintenance (2)		16,817				14,186			27,916				27,552
	General and administrative (3)		6,479				5,589			13,293				11,458
	Operating expenses		58,526				51,894			93,073				103,058
	Interest income, net (4)		4,225				4,225			8,450				8,450
	Distributions to unitholders (5)		56,325				40,247			108,207				77,115
	(1)	Represents amounts earned on and subsequent to the date of acquisition of the Partnership assets, as well as amounts earned 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 the Partnership assets by the Partnership.
	(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)	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	6 Months Ended
	Jun. 30, 2014
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	30-Jun-14		December 31, 2013
	Land	n/a	$	2,584	$	2,584
	Gathering systems	3 to 47 years	4,123,786		3,673,008
	Pipelines and equipment	15 to 45 years	145,799		146,008
	Assets under construction	n/a	304,854		405,633
	Other	3 to 40 years	14,912		11,867
	Total property, plant and equipment		4,591,935		4,239,100
	Accumulated depreciation		936,568		855,845
	Net property, plant and equipment		$	3,655,367	$	3,383,255
	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.
	At December 31, 2013, other long-term assets includes $4.6 million of unguaranteed residual value related to the capital lease component of a processing agreement assumed in connection with the acquisition of the Granger straddle plant as a part of the Mountain Gas Resources, LLC acquisition in January 2012. This agreement, in which the Partnership was the lessor, was replaced effective April 1, 2014, with a gas conditioning agreement that does not satisfy criteria required for lease classification. As such, during the second quarter of 2014, the Partnership reclassified the $4.6 million capital lease asset from other long-term assets to property, plant and equipment and commenced depreciation.
	During the second quarter of 2014, the Partnership recognized a $0.3 million impairment primarily related to the cancellation of various capital projects by the third-party operator of the Non-Operated Marcellus Interest. During the first quarter of 2014, the Partnership recognized a $1.2 million impairment primarily related to a non-operational plant in the Powder River Basin that was impaired to its estimated fair value of $2.4 million, using Level 3 fair-value inputs.

Components_of_Working_Capital

Components of Working Capital	6 Months Ended
	Jun. 30, 2014
Components Of Working Capital [Abstract]	'
Components of Working Capital	'
	7.  COMPONENTS OF WORKING CAPITAL
	A summary of other current assets is as follows:
	thousands	June 30,		December 31,
		2014		2013
	Natural gas liquids inventory	$	2,188	$	2,584
	Natural gas imbalance receivables	974		3,605
	Prepaid insurance	349		2,123
	Other	1,049		1,710
	Total other current assets	$	4,560	$	10,022
	7.  COMPONENTS OF WORKING CAPITAL (CONTINUED)
	A summary of accrued liabilities is as follows:
	thousands	June 30,		December 31,
		2014		2013
	Accrued capital expenditures	$	77,996	$	94,750
	Accrued plant purchases	28,333		21,396
	Accrued interest expense	25,492		18,119
	Short-term asset retirement obligations	605		1,966
	Short-term remediation and reclamation obligations	562		562
	Other	81		218
	Total accrued liabilities	$	133,069	$	137,011

Debt_and_Interest_Expense

Debt and Interest Expense	6 Months Ended
	Jun. 30, 2014
Debt Instruments [Abstract]	'
Debt and Interest Expense	'
	8.  DEBT AND INTEREST EXPENSE
	At June 30, 2014, 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”), and the senior unsecured revolving credit facility (“RCF”). The two tranches of the 2022 Notes, issued in June and October 2012, were issued under the same indenture and are considered a single class of securities. The two tranches of the 2018 Notes, issued in August 2013 and March 2014, were issued under the same indenture and are considered a single class of securities.
	The following table presents the Partnership’s outstanding debt as of June 30, 2014, and December 31, 2013:
			30-Jun-14									31-Dec-13
	thousands		Principal			Carrying			Fair			Principal			Carrying		Fair
						Value			Value (1)						Value		Value (1)
	5.375% Senior Notes due 2021		$	500,000		$	495,439		$	566,283		$	500,000		$	495,173	$	533,615
	4.000% Senior Notes due 2022		670,000			673,105			697,141			670,000			673,278		641,237
	Revolving credit facility		110,000			110,000			110,000			—			—		—
	2.600% Senior Notes due 2018		350,000			350,537			358,515			250,000			249,718		247,988
	5.450% Senior Notes due 2044		400,000			393,795			441,083			—			—		—
	Total debt outstanding		$	2,030,000		$	2,022,876		$	2,173,022		$	1,420,000		$	1,418,169	$	1,422,840
	(1)	Fair value is measured using Level 2 inputs.
	Debt activity. The following table presents the debt activity of the Partnership for the six months ended June 30, 2014:
	thousands		Carrying Value
	Balance at December 31, 2013		$	1,418,169
	Revolving credit facility borrowings		590,000
	Issuance of 5.450% Senior Notes due 2044		400,000
	Issuance of 2.600% Senior Notes due 2018		100,000
	Repayments of revolving credit facility		(480,000		)
	Other		(5,293		)
	Balance at June 30, 2014		$	2,022,876
	8.  DEBT AND INTEREST EXPENSE (CONTINUED)
	Senior Notes. The 2044 Notes issued in March 2014 were offered at a price to the public of 98.443% of the face amount. Including the effects of the issuance and underwriting discounts, the effective interest rate of the 2044 Notes is 5.633%. Interest is paid semi-annually on April 1 and October 1 of each year. Proceeds (net of underwriting discount of $3.5 million, original issue discount and debt issuance costs) were used to repay amounts then outstanding under the Partnership’s RCF and for general partnership purposes.
	The 2018 Notes issued in March 2014 were offered at a price to the public of 100.857% of the face amount. Including the effects of the issuance premium for the March 2014 offering, the issuance discount for the August 2013 offering of 2018 Notes, and underwriting discounts, the effective interest rate of the 2018 Notes is 2.743%. Interest is paid semi-annually on February 15 and August 15 of each year. Proceeds (net of underwriting discount of $0.6 million, original issue premium and debt issuance costs) were used to repay amounts then outstanding under the Partnership’s RCF and for general partnership purposes.
	At June 30, 2014, the Partnership was in compliance with all covenants under the indentures governing the 2021 Notes, 2022 Notes, 2018 Notes, and 2044 Notes.
	Revolving credit facility. In February 2014, the Partnership entered into an amended and restated $1.2 billion senior unsecured RCF, which is expandable to a maximum of $1.5 billion, replacing an $800.0 million credit facility, which was originally entered into in March 2011. Subsequent to February 2014, the Partnership borrowed $350.0 million under the RCF to fund the acquisition of the TEFR Interests (see Note 2). The RCF matures in February 2019 and bears interest at London Interbank Offered Rate (“LIBOR”), plus applicable margins ranging from 0.975% to 1.45%, or an alternate base rate equal to the greatest of (a) the Prime Rate, (b) the Federal Funds Effective Rate plus 0.5%, or (c) LIBOR plus 1%, in each case plus applicable margins currently ranging from zero to 0.45%, based upon the Partnership’s senior unsecured debt rating. The interest rate on the RCF was 1.46% at June 30, 2014. At December 31, 2013, the interest rate on the previous credit facility was 1.67%. The Partnership is required to pay a quarterly facility fee currently ranging from 0.15% to 0.30% of the commitment amount (whether used or unused), based upon the Partnership’s senior unsecured debt rating. The facility fee rate was 0.20% and 0.25% at June 30, 2014, and December 31, 2013, respectively.
	As of June 30, 2014, the Partnership had $110.0 million of outstanding borrowings, $12.8 million in outstanding letters of credit and $1.1 billion available for borrowing under the RCF. At June 30, 2014, the Partnership was in compliance with all covenants under the RCF.
	The 2021 Notes, 2022 Notes, 2018 Notes, 2044 Notes and obligations under the RCF are recourse to the Partnership’s general partner. The Partnership’s general partner is indemnified by a wholly owned subsidiary of Anadarko, Western Gas Resources, Inc. (“WGRI”), against any claims made against the general partner under the 2022 Notes, 2021 Notes, and/or the RCF.
	In connection with the acquisitions of the Non-Operated Marcellus Interest, the Anadarko-Operated Marcellus Interest, and the TEFR Interests, the Partnership’s general partner and other wholly owned subsidiaries of Anadarko entered into indemnification agreements, whereby such subsidiaries agreed to indemnify the Partnership’s general partner for any recourse liability it may have for RCF borrowings, or other debt financing, attributable to the acquisitions of the Non-Operated Marcellus Interest, the Anadarko-Operated Marcellus Interest, and the TEFR Interests. These indemnification agreements apply to the 2044 Notes, 2018 Notes, and/or RCF borrowings outstanding related to the aforementioned acquisitions.
	The Partnership’s general partner, the other indemnifying subsidiaries of Anadarko and WGRI also amended and restated the indemnity agreements between them to (i) conform language among all the indemnification agreements and (ii) reduce the amount for which WGRI would indemnify the Partnership’s general partner by an amount equal to any amounts payable to the Partnership’s general partner under the indemnification agreements related to the acquisitions of the Non-Operated Marcellus Interest, the Anadarko-Operated Marcellus Interest, and the TEFR Interests.
	8.  DEBT AND INTEREST EXPENSE (CONTINUED)
	Interest expense. The following table summarizes the amounts included in interest expense:
			Three Months Ended						Six Months Ended
			June 30,						June 30,
	thousands		2014			2013			2014			2013
	Interest expense on long-term debt		$	21,445		$	14,850		$	37,580		$	28,789
	Amortization of debt issuance costs and commitment fees		1,426			1,064			2,692			2,117
	Capitalized interest		(2,007		)	(3,260		)	(5,447		)	(6,441		)
	Interest expense		$	20,864		$	12,654		$	34,825		$	24,465

Commitments_and_Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	9.  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.
	In July 2011, the Court denied the defendants’ motion to dismiss without ruling on the merits and the case is in the discovery phase. 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 for which a final disposition 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 June 30, 2014, the Partnership had unconditional payment obligations for services to be rendered or products to be delivered in connection with its capital projects of $58.3 million, the majority of which is expected to be paid in the next twelve months. These commitments relate primarily to the continued construction of Train II at the Lancaster processing plant and compressor expansion projects at the Wattenberg system, both located in 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. 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 2015 and includes an early termination clause.
	Rent expense associated with the office, warehouse and equipment leases was $0.7 million and $1.5 million for the three and six months ended June 30, 2014, respectively, and $0.7 million and $1.4 million for the three and six months ended June 30, 2013, respectively.

Description_of_Business_and_Ba1

Description of Business and Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Business combinations policy	'
	Presentation of Partnership assets. References to the “Partnership assets” refer collectively to the assets owned and interests accounted for under the equity method by the Partnership as of June 30, 2014. Because Anadarko controls the Partnership through its ownership and control of WGP, which owns the Partnership’s general partner, each acquisition of the 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 the Partnership assets from Anadarko, the Partnership may be required to recast its financial statements to include the activities of the Partnership assets as of 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 for purposes of calculating net income per common unit.
	TEFR Interests acquisition. Because the acquisition of the TEFR Interests 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 TEFR Interests as if the Partnership owned the TEFR Interests for all periods presented. The consolidated financial statements for periods prior to the Partnership’s acquisition of the TEFR Interests 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 TEFR Interests during the periods reported.
Net income per common unit policy	'
	The Partnership’s net income earned on and subsequent to the date of the acquisition of the Partnership assets (as defined in Note 1) is allocated to the general partner and the limited partners consistent with actual cash distributions, including incentive distributions allocable to the general partner. Undistributed earnings (net income in excess of distributions) or undistributed losses (available cash in excess of net income) are then allocated to the general partner and the limited partners in accordance with their respective ownership percentages.
Fair value policy	'
	Note receivable from 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 $336.9 million and $296.7 million at June 30, 2014, and December 31, 2013, 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.
	During 2014, the Partnership recognized a $1.2 million impairment primarily related to a non-operational plant in the Powder River Basin that was impaired to its estimated fair value of $2.4 million, using Level 3 fair-value 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 under the particular circumstances. 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.

Description_of_Business_and_Ba2

Description of Business and Basis of Presentation (tables)	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
Assets Table	'
	As of June 30, 2014, the Partnership’s assets and investments accounted for under the equity method consisted of the following:
			Owned and		Operated			Non-Operated			Equity Interests
			Operated		Interests			Interests
	Natural gas gathering systems		13		1			5			2
	NGL gathering systems		—		—			—			2
	Natural gas treating facilities		8		—			—			1
	Natural gas processing facilities		9		3			—			2
	NGL pipelines		3		—			—			2
	Natural gas pipelines		3		—			—			—
	Oil pipeline		—		—			—			1
Equity Investments Table	'
	The following table presents the activity in the Partnership’s equity investments in Fort Union, White Cliffs, Rendezvous, the Mont Belvieu JV, TEG, TEP and FRP for the six months ended June 30, 2014:
		Equity Investments
	thousands	Fort			White				Rendezvous			Mont			TEG			TEP			FRP			Total
		Union			Cliffs							Belvieu JV
	Balance at December 31, 2013	$	25,172		$	35,039			$	60,928		$	122,480		$	16,649		$	197,731		$	135,401		$	593,400
	Investment earnings (loss), net of amortization	3,199			4,906				687			14,713			317			(53		)	(1,510		)	22,259
	Contributions	—			10,000				—			3,956			352			5,773			37,522			57,603
	Capitalized interest	—			—				—			—			—			—			857			857
	Distributions	(3,637		)	(4,616		)		(1,658		)	(16,510		)	(372		)	—			—			(26,793		)
	Distributions in excess of cumulative earnings (1)	—			(885		)		(1,395		)	—			(338		)	(3,710		)	(3,520		)	(9,848		)
	Balance at June 30, 2014	$	24,734		$	44,444			$	58,562		$	124,639		$	16,608		$	199,741		$	168,750		$	637,478
	(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.

Acquisitions_tables

Acquisitions (tables)	6 Months Ended
	Jun. 30, 2014
Business Combinations [Abstract]	'
Acquisitions Table	'
	The following table presents the acquisitions completed by the Partnership during 2014 and 2013, and identifies the funding sources for such acquisitions:
	thousands except unit and percent amounts		Acquisition		Percentage			Borrowings			Cash		Common
			Date		Acquired						On Hand		Units Issued
	Non-Operated Marcellus Interest (1)		3/1/13		33.75	%		$	250,000		$	215,500	449,129
	Anadarko-Operated Marcellus Interest (2)		3/8/13		33.75	%		133,500			—		—
	Mont Belvieu JV (3)		6/5/13		25	%		—			78,129		—
	OTTCO (4)		9/3/13		100	%		27,500			—		—
	TEFR Interests (5)		3/3/14		Various (5)			350,000			6,250		308,490
	(1)	The Partnership acquired Anadarko’s 33.75% interest (non-operated) in the Liberty and Rome gas gathering systems, serving production from the Marcellus shale in north-central Pennsylvania. The interest acquired is referred to as the “Non-Operated Marcellus Interest.” In connection with the issuance of the common units, the Partnership’s general partner purchased 9,166 general partner units for consideration of $0.5 million to maintain its 2.0% general partner interest in the Partnership.
	(2)	The Partnership acquired a 33.75% interest in each of the Larry’s Creek, Seely and Warrensville gas gathering systems, which are operated by Anadarko and serve production from the Marcellus shale in north-central Pennsylvania, from a third party. The interest acquired is referred to as the “Anadarko-Operated Marcellus Interest.” During the third quarter of 2013, the Partnership recorded a $1.1 million decrease in the assets acquired and liabilities assumed in the acquisition, representing the final purchase price allocation.
	(3)	The Partnership acquired a 25% interest in the Mont Belvieu JV, an entity formed to design, construct, and own two fractionation trains located in Mont Belvieu, Texas, from a third party. The interest acquired is accounted for under the equity method of accounting.
	(4)	The Partnership acquired Overland Trail Transmission, LLC (“OTTCO”), a Delaware limited liability company, from a third party. OTTCO owns and operates an intrastate pipeline that connects the Partnership’s Red Desert and Granger complexes in southwestern Wyoming.
	(5)	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 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’s general partner purchased 6,296 general partner units for consideration of $0.4 million to maintain its 2.0% general partner interest in the Partnership.
Impact to Historical Consolidated Statement of Income Table	'
	The following table presents the impact of the TEFR Interests on revenue, equity income (loss), net and net income as presented in the Partnership’s historical consolidated statements of income:
			Three Months Ended June 30, 2013
	thousands		Partnership Historical				TEFR Interests			Combined
	Revenues		$	251,402			$	—		$	251,402
	Equity income (loss), net		3,724				(268		)	3,456
	Net income (loss)		$	62,060			$	(184	)	$	61,876
			Six Months Ended June 30, 2013
	thousands		Partnership Historical				TEFR Interests			Combined
	Revenues		$	477,168			$	—		$	477,168
	Equity income (loss), net		7,705				(281		)	7,424
	Net income (loss)		$	114,948			$	(127	)	$	114,821

Partnership_Distributions_tabl

Partnership Distributions (tables)	6 Months Ended
	Jun. 30, 2014
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 unitholders for the periods presented:
	thousands except per-unit amounts		Total Quarterly		Total Quarterly		Date of
	Quarters Ended		Distribution		Cash Distribution		Distribution
			per Unit
	2013
	31-Mar-13		$	0.54	$	70,143	May 2013
	30-Jun-13		$	0.56	$	79,315	Aug-13
	2014
	31-Mar-14		$	0.625	$	98,749	May 2014
	June 30, 2014 (1)		$	0.65	$	105,655	Aug-14
	(1)	On July 18, 2014, the board of directors of the Partnership’s general partner declared a cash distribution to the Partnership’s unitholders of $0.650 per unit, or $105.7 million in aggregate, including incentive distributions. The cash distribution is payable on August 13, 2014, to unitholders of record at the close of business on July 31, 2014.

Equity_and_Partners_Capital_ta

Equity and Partners' Capital (tables)	6 Months Ended
	Jun. 30, 2014
Partners' Capital Notes [Abstract]	'
Equity Offerings Table	'
	The Partnership completed the following public offerings of its common units during 2014 and 2013:
	thousands except unit	Common		GP Units		Price Per		Underwriting		Net
	and per-unit amounts	Units Issued		Issued (1)		Unit		Discount and		Proceeds
								Other Offering
								Expenses
	May 2013 equity offering (2)	7,015,000		143,163		$	61.18	$	13,203	$	424,733
	December 2013 equity offering (3)	4,800,000		97,959		61.51		9,447		291,827
	Continuous Offering Program - 2013 (4)	685,735		13,996		60.84		965		41,603
	Continuous Offering Program - 2014 (5)	1,034,587		1,824		73.24		1,565		74,343
	(1)	Represents general partner units issued to the general partner in exchange for the general partner’s proportionate capital contribution to maintain its 2.0% general partner interest in the Partnership.
	(2)	Includes the issuance of 915,000 common units pursuant to the full exercise of the underwriters’ over-allotment option granted in connection with the May 2013 equity offering.
	(3)	Includes the issuance of 300,000 common units on January 3, 2014, pursuant to the partial exercise of the underwriters’ over-allotment option granted in connection with the December 2013 equity offering. Net proceeds from this partial exercise (including the general partner’s proportionate capital contribution) were $18.1 million.
	(4)	Represents common and general partner units issued during the year ended December 31, 2013, 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 “Continuous Offering Program”). Gross proceeds generated (including the general partner’s proportionate capital contributions) were $42.6 million. The price per unit in the table above represents an average price for all issuances under the Continuous Offering Program during 2013.
	(5)	Represents common and general partner units issued during the three and six months ended June 30, 2014, under the Continuous Offering Program. Gross proceeds generated (including the general partner’s proportionate capital contributions) were $75.9 million. The price per unit in the table above represents an average price for all issuances under the Continuous Offering Program during the six months ended June 30, 2014. Does not include the issuance of 98,797 common units that were sold in June 2014, but settled in July 2014, or the issuance of 21,308 general partner units to the general partner in exchange for the general partner’s proportionate capital contribution to maintain its 2.0% general partner interest in the Partnership.
Limited Partner and General Partner Units Table	'
	The following table summarizes common and general partner units issued during the six months ended June 30, 2014:
			Common		General		Total
			Units		Partner Units
	Balance at December 31, 2013		117,322,812		2,394,345		119,717,157
	December 2013 equity offering		300,000		6,122		306,122
	Long-Term Incentive Plan awards		5,418		112		5,530
	TEFR Interests acquisition		308,490		6,296		314,786
	Continuous Offering Program		1,034,587		1,824		1,036,411
	Balance at June 30, 2014		118,971,307		2,408,699		121,380,006

Transactions_With_Affiliates_t

Transactions With Affiliates (tables)	6 Months Ended
	Jun. 30, 2014
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 the Partnership’s outstanding commodity price swap agreements as of June 30, 2014:
	per barrel except natural gas		2014							2015							2016
	Ethane		$	18.36		−	$	30.53		$	18.41		−	$	23.41		$	23.11
	Propane		$	40.38		−	$	53.78		$	47.08		−	$	52.99		$	52.9
	Isobutane		$	61.24		−	$	75.13		$	62.09		−	$	74.02		$	73.89
	Normal butane		$	53.89		−	$	66.83		$	54.62		−	$	65.04		$	64.93
	Natural gasoline		$	71.85		−	$	90.89		$	72.88		−	$	81.82		$	81.68
	Condensate		$	75.22		−	$	87.3		$	76.47		−	$	81.82		$	81.68
	Natural gas (per MMBtu)		$	3.45		−	$	6.2		$	4.66		−	$	5.96		$	4.87
Gains (Losses) on Commodity Price Swap Agreements Table	'
	The following table summarizes realized gains and losses on commodity price swap agreements:
			Three Months Ended							Six Months Ended
			June 30,							June 30,
	thousands		2014				2013			2014				2013
	Gains (losses) on commodity price swap agreements related to sales: (1)
	Natural gas sales		$	2,013			$	2,404		$	(1,654	)		$	7,784
	Natural gas liquids sales		34,554				34,203			44,009				55,508
	Total		36,567				36,607			42,355				63,292
	Losses on commodity price swap agreements related to purchases (2)		(18,529		)		(22,857		)	(18,548		)		(42,711		)
	Net gains (losses) on commodity price swap agreements		$	18,038			$	13,750		$	23,807			$	20,581
	(1)	Reported in affiliate natural gas, natural gas liquids and 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.
Related Party Transactions Tables	'
	The following table summarizes the Partnership’s purchases from and sales to Anadarko of pipe and equipment:
			Six Months Ended June 30,
			2014				2013			2014				2013
	thousands		Purchases							Sales
	Cash consideration		$	4,702			$	1,436		$	—			$	82
	Net carrying value		4,745				773			—				34
	Partners’ capital adjustment		$	(43	)		$	663		$	—			$	48
	The following table summarizes affiliate transactions, which include revenue from affiliates, reimbursement of operating expenses and purchases of natural gas:
			Three Months Ended							Six Months Ended
			June 30,							June 30,
	thousands		2014				2013			2014				2013
	Revenues (1)		$	256,666			$	200,316		$	462,956			$	377,885
	Equity income, net		13,008				3,456			22,259				7,424
	Cost of product (1)		35,230				32,119			51,864				64,048
	Operation and maintenance (2)		16,817				14,186			27,916				27,552
	General and administrative (3)		6,479				5,589			13,293				11,458
	Operating expenses		58,526				51,894			93,073				103,058
	Interest income, net (4)		4,225				4,225			8,450				8,450
	Distributions to unitholders (5)		56,325				40,247			108,207				77,115
	(1)	Represents amounts 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 by the Partnership.
	(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)	Represents distributions paid under the partnership agreement (see Note 3 and Note 4).

Property_Plant_and_Equipment_t

Property, Plant and Equipment (table)	6 Months Ended
	Jun. 30, 2014
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	30-Jun-14		December 31, 2013
	Land	n/a	$	2,584	$	2,584
	Gathering systems	3 to 47 years	4,123,786		3,673,008
	Pipelines and equipment	15 to 45 years	145,799		146,008
	Assets under construction	n/a	304,854		405,633
	Other	3 to 40 years	14,912		11,867
	Total property, plant and equipment		4,591,935		4,239,100
	Accumulated depreciation		936,568		855,845
	Net property, plant and equipment		$	3,655,367	$	3,383,255

Components_of_Working_Capital_

Components of Working Capital (tables)	6 Months Ended
	Jun. 30, 2014
Components Of Working Capital [Abstract]	'
Other Current Assets Table	'
	A summary of other current assets is as follows:
	thousands	June 30,		December 31,
		2014		2013
	Natural gas liquids inventory	$	2,188	$	2,584
	Natural gas imbalance receivables	974		3,605
	Prepaid insurance	349		2,123
	Other	1,049		1,710
	Total other current assets	$	4,560	$	10,022
Accrued Liabilities Table	'
	A summary of accrued liabilities is as follows:
	thousands	June 30,		December 31,
		2014		2013
	Accrued capital expenditures	$	77,996	$	94,750
	Accrued plant purchases	28,333		21,396
	Accrued interest expense	25,492		18,119
	Short-term asset retirement obligations	605		1,966
	Short-term remediation and reclamation obligations	562		562
	Other	81		218
	Total accrued liabilities	$	133,069	$	137,011

Debt_and_Interest_Expense_tabl

Debt and Interest Expense (tables)	6 Months Ended
	Jun. 30, 2014
Debt Instruments [Abstract]	'
Debt Outstanding and Debt Activity Tables	'
	The following table presents the Partnership’s outstanding debt as of June 30, 2014, and December 31, 2013:
			30-Jun-14									31-Dec-13
	thousands		Principal			Carrying			Fair			Principal			Carrying		Fair
						Value			Value (1)						Value		Value (1)
	5.375% Senior Notes due 2021		$	500,000		$	495,439		$	566,283		$	500,000		$	495,173	$	533,615
	4.000% Senior Notes due 2022		670,000			673,105			697,141			670,000			673,278		641,237
	Revolving credit facility		110,000			110,000			110,000			—			—		—
	2.600% Senior Notes due 2018		350,000			350,537			358,515			250,000			249,718		247,988
	5.450% Senior Notes due 2044		400,000			393,795			441,083			—			—		—
	Total debt outstanding		$	2,030,000		$	2,022,876		$	2,173,022		$	1,420,000		$	1,418,169	$	1,422,840
	(1)	Fair value is measured using Level 2 inputs.
	Debt activity. The following table presents the debt activity of the Partnership for the six months ended June 30, 2014:
	thousands		Carrying Value
	Balance at December 31, 2013		$	1,418,169
	Revolving credit facility borrowings		590,000
	Issuance of 5.450% Senior Notes due 2044		400,000
	Issuance of 2.600% Senior Notes due 2018		100,000
	Repayments of revolving credit facility		(480,000		)
	Other		(5,293		)
	Balance at June 30, 2014		$	2,022,876
Interest Expense Table	'
	The following table summarizes the amounts included in interest expense:
			Three Months Ended						Six Months Ended
			June 30,						June 30,
	thousands		2014			2013			2014			2013
	Interest expense on long-term debt		$	21,445		$	14,850		$	37,580		$	28,789
	Amortization of debt issuance costs and commitment fees		1,426			1,064			2,692			2,117
	Capitalized interest		(2,007		)	(3,260		)	(5,447		)	(6,441		)
	Interest expense		$	20,864		$	12,654		$	34,825		$	24,465

Description_of_Business_and_Ba3

Description of Business and Basis of Presentation - Asset Table (details)	Jun. 30, 2014
Operated [Member] | Natural Gas Gathering System [Member]	'
Assets [Line Items]	'
Assets, number of units	13
Operated [Member] | Natural Gas Treating Facilities [Member]	'
Assets [Line Items]	'
Assets, number of units	8
Operated [Member] | Natural Gas Processing Facilities [Member]	'
Assets [Line Items]	'
Assets, number of units	9
Operated [Member] | Natural Gas Liquids Pipeline [Member]	'
Assets [Line Items]	'
Assets, number of units	3
Operated [Member] | Natural Gas Pipelines [Member]	'
Assets [Line Items]	'
Assets, number of units	3
Operated Interest [Member] | Natural Gas Gathering System [Member]	'
Assets [Line Items]	'
Assets, number of units	1
Operated Interest [Member] | Natural Gas Processing Facilities [Member]	'
Assets [Line Items]	'
Assets, number of units	3
Non Operated Interest [Member] | Natural Gas Gathering System [Member]	'
Assets [Line Items]	'
Assets, number of units	5
Equity Investments [Member] | Natural Gas Gathering System [Member]	'
Assets [Line Items]	'
Assets, number of units	2
Equity Investments [Member] | Natural Gas Liquids Gathering System [Member]	'
Assets [Line Items]	'
Assets, number of units	2
Equity Investments [Member] | Natural Gas Treating Facilities [Member]	'
Assets [Line Items]	'
Assets, number of units	1
Equity Investments [Member] | Natural Gas Processing Facilities [Member]	'
Assets [Line Items]	'
Assets, number of units	2
Equity Investments [Member] | Natural Gas Liquids Pipeline [Member]	'
Assets [Line Items]	'
Assets, number of units	2
Equity Investments [Member] | Oil pipeline [Member]	'
Assets [Line Items]	'
Assets, number of units	1

Description_of_Business_and_Ba4

Description of Business and Basis of Presentation - Equity Investments Table (details) (USD $)	3 Months Ended				6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Schedule of Equity Method Investments [Line Items]	'		'		'		'
Balance	'		'		$593,400	[1]	'
Investment earnings (loss), net of amortization	13,008	[2]	3,456	[1],[2]	22,259	[2],[3]	7,424	[1],[2],[3]
Contributions	'		'		59,245		156,217	[1]
Capitalized interest	'		'		857		7,195	[1]
Distributions	'		'		-26,793	[3]	-11,032	[1],[3]
Distributions in excess of cumulative earnings	'		'		-9,848	[3],[4]	0	[1],[3]
Balance	637,478		'		637,478		'
Fort Union [Member]	'		'		'		'
Schedule of Equity Method Investments [Line Items]	'		'		'		'
Balance	'		'		25,172		'
Investment earnings (loss), net of amortization	'		'		3,199		'
Contributions	'		'		0		'
Capitalized interest	'		'		0		'
Distributions	'		'		-3,637		'
Distributions in excess of cumulative earnings	'		'		0	[4]	'
Balance	24,734		'		24,734		'
White Cliffs [Member]	'		'		'		'
Schedule of Equity Method Investments [Line Items]	'		'		'		'
Balance	'		'		35,039		'
Investment earnings (loss), net of amortization	'		'		4,906		'
Contributions	'		'		10,000		'
Capitalized interest	'		'		0		'
Distributions	'		'		-4,616		'
Distributions in excess of cumulative earnings	'		'		-885	[4]	'
Balance	44,444		'		44,444		'
Rendezvous [Member]	'		'		'		'
Schedule of Equity Method Investments [Line Items]	'		'		'		'
Balance	'		'		60,928		'
Investment earnings (loss), net of amortization	'		'		687		'
Contributions	'		'		0		'
Capitalized interest	'		'		0		'
Distributions	'		'		-1,658		'
Distributions in excess of cumulative earnings	'		'		-1,395	[4]	'
Balance	58,562		'		58,562		'
Mont Belvieu Joint Venture [Member]	'		'		'		'
Schedule of Equity Method Investments [Line Items]	'		'		'		'
Balance	'		'		122,480		'
Investment earnings (loss), net of amortization	'		'		14,713		'
Contributions	'		'		3,956		'
Capitalized interest	'		'		0		'
Distributions	'		'		-16,510		'
Distributions in excess of cumulative earnings	'		'		0	[4]	'
Balance	124,639		'		124,639		'
Texas Express Gathering Limited Liability Company [Member]	'		'		'		'
Schedule of Equity Method Investments [Line Items]	'		'		'		'
Balance	'		'		16,649		'
Investment earnings (loss), net of amortization	'		'		317		'
Contributions	'		'		352		'
Capitalized interest	'		'		0		'
Distributions	'		'		-372		'
Distributions in excess of cumulative earnings	'		'		-338	[4]	'
Balance	16,608		'		16,608		'
Texas Express Pipeline Limited Liability Company [Member]	'		'		'		'
Schedule of Equity Method Investments [Line Items]	'		'		'		'
Balance	'		'		197,731		'
Investment earnings (loss), net of amortization	'		'		-53		'
Contributions	'		'		5,773		'
Capitalized interest	'		'		0		'
Distributions	'		'		0		'
Distributions in excess of cumulative earnings	'		'		-3,710	[4]	'
Balance	199,741		'		199,741		'
Front Range Pipeline Limited Liability Company [Member]	'		'		'		'
Schedule of Equity Method Investments [Line Items]	'		'		'		'
Balance	'		'		135,401		'
Investment earnings (loss), net of amortization	'		'		-1,510		'
Contributions	'		'		37,522		'
Capitalized interest	'		'		857		'
Distributions	'		'		0		'
Distributions in excess of cumulative earnings	'		'		-3,520	[4]	'
Balance	168,750		'		168,750		'
Equity Investments [Member]	'		'		'		'
Schedule of Equity Method Investments [Line Items]	'		'		'		'
Contributions	'		'		$57,603		'
[1]	Financial information has been recast to include the financial position and results attributable to the TEFR Interests. 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]	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.

Description_of_Business_and_Ba5

Description of Business and Basis of Presentation - Additional Information (details)	6 Months Ended
	Jun. 30, 2014
General partner's interest	2.00%
Western Gas Equity Partners [Member]	'
General partner's interest	2.00%
Ownership interest	100.00%
Incentive Distribution Rights [Member] | Western Gas Equity Partners [Member]	'
General partner's interest	100.00%
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 Joint Venture [Member]	'
Equity investment ownership	25.00%
Texas Express Pipeline Limited Liability Company [Member]	'
Equity investment ownership	20.00%
Texas Express Gathering Limited Liability Company [Member]	'
Equity investment ownership	20.00%
Front Range Pipeline Limited Liability Company [Member]	'
Equity investment ownership	33.33%
Non-Operated Marcellus Interest [Member]	'
Ownership interest	33.75%
Anadarko-Operated Marcellus Interest [Member]	'
Ownership interest	33.75%
Newcastle [Member]	'
Ownership interest	50.00%

Acquisitions_Acquisitions_Tabl

Acquisitions - Acquisitions Table (details) (USD $)

6 Months Ended

1 Months Ended

1 Months Ended

1 Months Ended

1 Months Ended

Jun. 30, 2014

Jun. 30, 2013

Dec. 31, 2013

Mar. 31, 2013

Mar. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Sep. 30, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Non-Operated Marcellus Interest [Member]

Anadarko-Operated Marcellus Interest [Member]

Anadarko-Operated Marcellus Interest [Member]

Mont Belvieu Joint Venture [Member]

Mont Belvieu Joint Venture [Member]

Overland Trail Transmission Limited Liability Company [Member]

Texas Express And Front Range [Member]

Texas Express Gathering Limited Liability Company [Member]

Texas Express Pipeline Limited Liability Company [Member]

Front Range Pipeline Limited Liability Company [Member]

Common Units [Member]

Common Units [Member]

Fractionator [Member]

Non-Operated Marcellus Interest [Member]

Texas Express And Front Range [Member]

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage acquired

'

'

'

33.75%

[1]

33.75%

[2]

'

'

'

100.00%

[3]

'

'

'

'

'

'

Equity investment ownership

'

'

'

'

'

'

25.00%

[4]

'

'

'

20.00%

20.00%

33.33%

'

'

Borrowings

$1,076,895,000

$494,948,000

[5]

'

$250,000,000

[1]

$133,500,000

[2]

'

'

'

$27,500,000

[3]

$350,000,000

[6]

'

'

'

'

'

Cash on hand

360,952,000

679,610,000

[5]

'

215,500,000

[1]

'

'

78,129,000

[4]

'

'

6,250,000

[6]

'

'

'

'

'

Units issued

'

'

'

'

'

'

'

'

'

'

'

'

'

449,129

[1]

308,490

[6]

Table Text Block Supplement [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

General partner units issued

2,408,699

'

2,394,345

9,166

'

'

'

'

'

6,296

'

'

'

'

'

Proceeds from the issuance of common and general partner units, net of offering expenses

92,588,000

425,386,000

[5]

'

500,000

'

'

'

'

'

400,000

'

'

'

'

'

General partner's interest

2.00%

'

'

2.00%

'

'

'

'

'

2.00%

'

'

'

'

'

Purchase price adjustment

'

'

'

'

'

$1,100,000

'

'

'

'

'

'

'

'

'

Assets, number of units

'

'

'

'

'

'

'

2

'

'

'

'

'

'

'

[1]

The Partnership acquired Anadarko’s 33.75% interest (non-operated) in the Liberty and Rome gas gathering systems, serving production from the Marcellus shale in north-central Pennsylvania. The interest acquired is referred to as the “Non-Operated Marcellus Interest.” In connection with the issuance of the common units, the Partnership’s general partner purchased 9,166 general partner units for consideration of $0.5 million to maintain its 2.0% general partner interest in the Partnership.

[2]

The Partnership acquired a 33.75% interest in each of the Larry’s Creek, Seely and Warrensville gas gathering systems, which are operated by Anadarko and serve production from the Marcellus shale in north-central Pennsylvania, from a third party. The interest acquired is referred to as the “Anadarko-Operated Marcellus Interest.” During the third quarter of 2013, the Partnership recorded a $1.1 million decrease in the assets acquired and liabilities assumed in the acquisition, representing the final purchase price allocation.

[3]

The Partnership acquired Overland Trail Transmission, LLC (“OTTCO”), a Delaware limited liability company, from a third party. OTTCO owns and operates an intrastate pipeline that connects the Partnership’s Red Desert and Granger complexes in southwestern Wyoming.

[4]

The Partnership acquired a 25% interest in the Mont Belvieu JV, an entity formed to design, construct, and own two fractionation trains located in Mont Belvieu, Texas, from a third party. The interest acquired is accounted for under the equity method of accounting

[5]

Financial information has been recast to include the financial position and results attributable to the TEFR Interests. See Note 1 and Note 2.

[6]

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 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’s general partner purchased 6,296 general partner units for consideration of $0.4 million to maintain its 2.0% general partner interest in the Partnership.

Acquisitions_Acquisitions_Impa

Acquisitions Acquisitions - Impact to Historical Consolidated Statement of Income Table (details) (USD $)	3 Months Ended				6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Revenues	$329,944		$251,402	[1]	$609,401		$477,168	[1]
Equity income, net	13,008	[2]	3,456	[1],[2]	22,259	[2],[3]	7,424	[1],[2],[3]
Net income	98,482		61,876	[1]	189,609		114,821	[1]
Partnership Historical [Member]	'		'		'		'
Revenues	'		251,402		'		477,168
Equity income, net	'		3,724		'		7,705
Net income	'		62,060		'		114,948
Texas Express And Front Range [Member]	'		'		'		'
Revenues	'		0		'		0
Equity income, net	'		-268		'		-281
Net income	'		($184)		'		($127)
[1]	Financial information has been recast to include the financial position and results attributable to the TEFR Interests. 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.

Partnership_Distributions_Cash

Partnership Distributions - Cash Distributions Table (details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2014		Mar. 31, 2014	Jun. 30, 2013	Mar. 31, 2013
Distributions Made to Members or Limited Partners [Abstract]	'		'	'	'
Total quarterly distribution per unit	$0.65	[1]	$0.63	$0.56	$0.54
Total quarterly cash distribution	$105,655	[1]	$98,749	$79,315	$70,143
[1]	On July 18, 2014, the board of directors of the Partnership’s general partner declared a cash distribution to the Partnership’s unitholders of $0.650 per unit, or $105.7 million in aggregate, including incentive distributions. The cash distribution is payable on August 13, 2014, to unitholders of record at the close of business on July 31, 2014.

Partnership_Distributions_Addi

Partnership Distributions - Additional Information (details)	6 Months Ended
	Jun. 30, 2014
Distributions Made to Members or Limited Partners [Abstract]	'
Partnership agreement day requirement of distribution of available cash	'45 days

Equity_and_Partners_Capital_Eq

Equity and Partners' Capital - Equity Offerings Table (details) (USD $)

1 Months Ended

6 Months Ended

1 Months Ended

6 Months Ended

12 Months Ended

6 Months Ended

12 Months Ended

1 Months Ended

6 Months Ended

12 Months Ended

1 Months Ended

Dec. 31, 2013

31-May-13

Jun. 30, 2014

Jan. 31, 2014

Dec. 31, 2013

31-May-13

Jan. 31, 2014

31-May-13

Dec. 31, 2013

31-May-13

Jun. 30, 2014

Dec. 31, 2013

Aug. 31, 2012

Jun. 30, 2014

Dec. 31, 2013

Jul. 31, 2014

Jun. 30, 2014

Dec. 31, 2013

Jul. 31, 2014

Option On Securities [Member]

Common Units [Member]

Common Units [Member]

Common Units [Member]

Common Units [Member]

General Partner [Member]

General Partner [Member]

Continuous Offering Program [Member]

Continuous Offering Program [Member]

Continuous Offering Program [Member]

Continuous Offering Program [Member]

Continuous Offering Program [Member]

Continuous Offering Program [Member]

Continuous Offering Program [Member]

Continuous Offering Program [Member]

Continuous Offering Program [Member]

Option On Securities [Member]

Option On Securities [Member]

Common Units [Member]

Common Units [Member]

Common Units [Member]

General Partner [Member]

General Partner [Member]

General Partner [Member]

Subsequent Event [Member]

Subsequent Event [Member]

Capital Unit [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common units issued

'

'

'

'

4,800,000

[1]

7,015,000

[2]

300,000

915,000

'

'

'

'

'

1,034,587

[3]

685,735

[4]

98,797

'

'

'

General partner units issued

'

'

'

'

'

'

'

'

97,959

[1],[5]

143,163

[2],[5]

1,036,411

'

'

'

'

'

1,824

[3],[5]

13,996

[4],[5]

21,308

Price per unit

$61.51

[1]

$61.18

[2]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Average price per unit

'

'

'

'

'

'

'

'

'

'

$73.24

[3]

$60.84

[4]

'

'

'

'

'

'

'

Underwriting discount and other offering expenses

$9,447,000

[1]

$13,203,000

[2]

'

'

'

'

'

'

'

'

$1,565,000

[3]

$965,000

[4]

'

'

'

'

'

'

'

Net proceeds

291,827,000

[1]

424,733,000

[2]

'

18,100,000

'

'

'

'

'

'

74,343,000

[3]

41,603,000

[4]

'

'

'

'

'

'

'

Table Text Block Supplement [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

General partner's interest

'

'

2.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maximum aggregate principal of common stock

'

'

'

'

'

'

'

'

'

'

'

'

125,000,000

'

'

'

'

'

'

Gross proceeds

'

'

'

'

'

'

'

'

'

'

$75,900,000

$42,600,000

'

'

'

'

'

'

'

[1]

Includes the issuance of 300,000 common units on January 3, 2014, pursuant to the partial exercise of the underwriters’ over-allotment option granted in connection with the December 2013 equity offering. Net proceeds from this partial exercise (including the general partner’s proportionate capital contribution) were $18.1 million.

[2]

Includes the issuance of 915,000 common units pursuant to the full exercise of the underwriters’ over-allotment option granted in connection with the May 2013 equity offering.

[3]

Represents common and general partner units issued during the three and six months ended June 30, 2014, under the Continuous Offering Program. Gross proceeds generated (including the general partner’s proportionate capital contributions) were $75.9 million. The price per unit in the table above represents an average price for all issuances under the Continuous Offering Program during the six months ended June 30, 2014. Does not include the issuance of 98,797 common units that were sold in June 2014, but settled in July 2014, or the issuance of 21,308 general partner units to the general partner in exchange for the general partner’s proportionate capital contribution to maintain its 2.0% general partner interest in the Partnership.

[4]

Represents common and general partner units issued during the year ended December 31, 2013, 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 “Continuous Offering Program”). Gross proceeds generated (including the general partner’s proportionate capital contributions) were $42.6 million. The price per unit in the table above represents an average price for all issuances under the Continuous Offering Program during 2013.

[5]

Represents general partner units issued to the general partner in exchange for the general partner’s proportionate capital contribution to maintain its 2.0% general partner interest in the Partnership.

Equity_and_Partners_Capital_Li

Equity and Partners' Capital - Limited Partner and General Partner Units (details)

6 Months Ended

1 Months Ended

6 Months Ended

12 Months Ended

1 Months Ended

6 Months Ended

12 Months Ended

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Dec. 31, 2013

31-May-13

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Dec. 31, 2013

Dec. 31, 2013

31-May-13

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Dec. 31, 2013

December 2013 Equity Offering [Member]

Texas Express And Front Range [Member]

Continuous Offering Program [Member]

Common Units [Member]

Common Units [Member]

Common Units [Member]

Common Units [Member]

Common Units [Member]

Common Units [Member]

Common Units [Member]

General Partner [Member]

General Partner [Member]

General Partner [Member]

General Partner [Member]

General Partner [Member]

General Partner [Member]

General Partner [Member]

December 2013 Equity Offering [Member]

Texas Express And Front Range [Member]

Continuous Offering Program [Member]

Continuous Offering Program [Member]

December 2013 Equity Offering [Member]

Texas Express And Front Range [Member]

Continuous Offering Program [Member]

Continuous Offering Program [Member]

Capital Unit [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Balance

119,717,157

'

'

'

'

'

117,322,812

'

'

'

'

'

'

2,394,345

'

'

'

'

Common units issued

'

'

'

'

4,800,000

[1]

7,015,000

[2]

'

300,000

'

1,034,587

[3]

685,735

[4]

'

'

'

'

'

'

'

Offering

'

306,122

'

1,036,411

'

'

'

'

'

'

'

97,959

[1],[5]

143,163

[2],[5]

'

6,122

'

1,824

[3],[5]

13,996

[4],[5]

Long-term incentive plan awards

5,530

'

'

'

'

'

5,418

'

'

'

'

'

'

112

'

'

'

'

Acquisition

'

'

314,786

'

'

'

'

'

308,490

'

'

'

'

'

'

6,296

'

'

Balance

121,380,006

'

'

'

117,322,812

'

118,971,307

'

'

'

'

2,394,345

'

2,408,699

'

'

'

'

[1]

Includes the issuance of 300,000 common units on January 3, 2014, pursuant to the partial exercise of the underwriters’ over-allotment option granted in connection with the December 2013 equity offering. Net proceeds from this partial exercise (including the general partner’s proportionate capital contribution) were $18.1 million.

[2]

Includes the issuance of 915,000 common units pursuant to the full exercise of the underwriters’ over-allotment option granted in connection with the May 2013 equity offering.

[3]

Represents common and general partner units issued during the three and six months ended June 30, 2014, under the Continuous Offering Program. Gross proceeds generated (including the general partner’s proportionate capital contributions) were $75.9 million. The price per unit in the table above represents an average price for all issuances under the Continuous Offering Program during the six months ended June 30, 2014. Does not include the issuance of 98,797 common units that were sold in June 2014, but settled in July 2014, or the issuance of 21,308 general partner units to the general partner in exchange for the general partner’s proportionate capital contribution to maintain its 2.0% general partner interest in the Partnership.

[4]

Represents common and general partner units issued during the year ended December 31, 2013, 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 “Continuous Offering Program”). Gross proceeds generated (including the general partner’s proportionate capital contributions) were $42.6 million. The price per unit in the table above represents an average price for all issuances under the Continuous Offering Program during 2013.

[5]

Represents general partner units issued to the general partner in exchange for the general partner’s proportionate capital contribution to maintain its 2.0% general partner interest in the Partnership.

Equity_and_Partners_Capital_Ad

Equity and Partners' Capital - Additional Information (details)	6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Schedule Of Investments [Line Items]	'	'
Common units owned	118,971,307	117,322,812
General partner units owned	2,408,699	2,394,345
General partner's interest	2.00%	'
Western Gas Equity Partners [Member]	'	'
Schedule Of Investments [Line Items]	'	'
Common units owned	49,296,205	'
Ownership interest	40.60%	'
General partner units owned	2,408,699	'
General partner's interest	2.00%	'
Other Subsidiaries Of Anadarko [Member]	'	'
Schedule Of Investments [Line Items]	'	'
Common units owned	757,619	'
Ownership interest	0.60%	'
Public [Member]	'	'
Schedule Of Investments [Line Items]	'	'
Common units owned	68,917,483	'
Ownership interest	56.80%	'
Incentive Distribution Rights [Member] | Western Gas Equity Partners [Member]	'	'
Schedule Of Investments [Line Items]	'	'
General partner's interest	100.00%	'

Transactions_With_Affiliates_C

Transactions With Affiliates - Commodity Price Per Unit Table (details)	Jun. 30, 2014
Ethane [Member] | Year 2016 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	23.11
Ethane [Member] | Minimum [Member] | Year 2014 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	18.36
Ethane [Member] | Minimum [Member] | Year 2015 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	18.41
Ethane [Member] | Maximum [Member] | Year 2014 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	30.53
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	52.9
Propane [Member] | Minimum [Member] | Year 2014 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	40.38
Propane [Member] | Minimum [Member] | Year 2015 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	47.08
Propane [Member] | Maximum [Member] | Year 2014 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	53.78
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 2014 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	61.24
Isobutane [Member] | Minimum [Member] | Year 2015 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	62.09
Isobutane [Member] | Maximum [Member] | Year 2014 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	75.13
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 2014 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	53.89
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 2014 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	66.83
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 2014 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	71.85
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 2014 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	90.89
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 2014 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	75.22
Condensate [Member] | Minimum [Member] | Year 2015 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	76.47
Condensate [Member] | Maximum [Member] | Year 2014 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	87.3
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	4.87
Natural Gas (per MMbtu) [Member] | Minimum [Member] | Year 2014 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	3.45
Natural Gas (per MMbtu) [Member] | Minimum [Member] | Year 2015 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	4.66
Natural Gas (per MMbtu) [Member] | Maximum [Member] | Year 2014 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	6.2
Natural Gas (per MMbtu) [Member] | Maximum [Member] | Year 2015 [Member]	'
Commodity Price Risk Swap [Line Items]	'
Commodity Swap Fixed Price	5.96

Transactions_With_Affiliates_G

Transactions With Affiliates - Gains Losses Commodity Price Swap Table (details) (USD $)	3 Months Ended				6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Gains (losses) on commodity price swap	'		'		'		'
Net gains (losses) on commodity price swap agreements	$18,038		$13,750		$23,807		$20,581
Sales [Member]	'		'		'		'
Gains (losses) on commodity price swap	'		'		'		'
Net gains (losses) on commodity price swap agreements	36,567	[1]	36,607	[1]	42,355	[1]	63,292	[1]
Sales [Member] | Natural Gas, Per Thousand Cubic Feet [Member]	'		'		'		'
Gains (losses) on commodity price swap	'		'		'		'
Net gains (losses) on commodity price swap agreements	2,013	[1]	2,404	[1]	-1,654	[1]	7,784	[1]
Sales [Member] | Natural Gas Liquids [Member]	'		'		'		'
Gains (losses) on commodity price swap	'		'		'		'
Net gains (losses) on commodity price swap agreements	34,554	[1]	34,203	[1]	44,009	[1]	55,508	[1]
Cost of Sales [Member]	'		'		'		'
Gains (losses) on commodity price swap	'		'		'		'
Net gains (losses) on commodity price swap agreements	($18,529)	[2]	($22,857)	[2]	($18,548)	[2]	($42,711)	[2]
[1]	Reported in affiliate natural gas, natural gas liquids and 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_E

Transactions With Affiliates - Equipment Purchases and Sales Table (details) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Related Party Transaction [Line Items]	'	'
Partners' capital adjustment	($43)	'
Partners' capital adjustment	'	615	[1]
Affiliated Entity [Member] | Purchases [Member]	'	'
Related Party Transaction [Line Items]	'	'
Consideration given for equipment	4,702	1,436
Net carrying value	4,745	773
Partners' capital adjustment	-43	'
Partners' capital adjustment	'	663
Affiliated Entity [Member] | Sales [Member]	'	'
Related Party Transaction [Line Items]	'	'
Consideration received for equipment	0	82
Net carrying value	0	34
Partners' capital adjustment	$0	($48)
[1]	Financial information has been recast to include the financial position and results attributable to the TEFR Interests. See Note 1 and Note 2.

Transactions_With_Affiliates_S

Transactions With Affiliates - Summary Table (details) (USD $)	3 Months Ended						6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014		Mar. 31, 2014	Jun. 30, 2013		Mar. 31, 2013	Jun. 30, 2014		Jun. 30, 2013
Related Party Transaction [Line Items]	'		'	'		'	'		'
Revenues	$329,944		'	$251,402	[1]	'	$609,401		$477,168	[1]
Equity income, net	13,008	[2]	'	3,456	[1],[2]	'	22,259	[2],[3]	7,424	[1],[2],[3]
Cost of product	118,085	[4]	'	93,460	[1],[4]	'	210,035	[4]	176,543	[1],[4]
Operation and maintenance	50,875	[4]	'	41,669	[1],[4]	'	91,407	[4]	78,408	[1],[4]
General and administrative	8,000	[4]	'	7,288	[1],[4]	'	16,415	[4]	14,952	[1],[4]
Operating expenses	227,819		'	184,999	[1]	'	416,369		350,710	[1]
Interest income, net	4,225	[5]	'	4,225	[1],[5]	'	8,450	[5]	8,450	[1],[5]
Distributions to unitholders	105,655	[6]	98,749	79,315		70,143	'		'
Affiliated Entity [Member]	'		'	'		'	'		'
Related Party Transaction [Line Items]	'		'	'		'	'		'
Revenues	256,666	[7]	'	200,316	[1],[7]	'	462,956	[7]	377,885	[1],[7]
Cost of product	35,230	[7]	'	32,119	[7]	'	51,864	[7]	64,048	[7]
Operation and maintenance	16,817	[8]	'	14,186	[8]	'	27,916	[8]	27,552	[8]
General and administrative	6,479	[9]	'	5,589	[9]	'	13,293	[9]	11,458	[9]
Operating expenses	58,526		'	51,894		'	93,073		103,058
Distributions to unitholders	$56,325	[10]	'	$40,247	[10]	'	$108,207	[10]	$77,115	[10]
[1]	Financial information has been recast to include the financial position and results attributable to the TEFR Interests. 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]	Cost of product includes product purchases from Anadarko (as defined in Note 1) of $35.2 million and $51.9 million for the three and six months ended June 30, 2014, respectively, and $32.1 million and $64.0 million for the three and six months ended June 30, 2013, respectively. Operation and maintenance includes charges from Anadarko of $16.8 million and $27.9 million for the three and six months ended June 30, 2014, respectively, and $14.2 million and $27.6 million for the three and six months ended June 30, 2013, respectively. General and administrative includes charges from Anadarko of $6.5 million and $13.3 million for the three and six months ended June 30, 2014, respectively, and $5.6 million and $11.5 million for the three and six months ended June 30, 2013, respectively. See Note 5
[5]	Represents interest income recognized on the note receivable from Anadarko.
[6]	On July 18, 2014, the board of directors of the Partnership’s general partner declared a cash distribution to the Partnership’s unitholders of $0.650 per unit, or $105.7 million in aggregate, including incentive distributions. The cash distribution is payable on August 13, 2014, to unitholders of record at the close of business on July 31, 2014.
[7]	Represents amounts earned on and subsequent to the date of acquisition of the Partnership assets, as well as amounts earned 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.
[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 the Partnership assets by the Partnership.
[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]	Represents distributions paid under the partnership agreement (see Note 3 and Note 4).

Transactions_With_Affiliates_A

Transactions With Affiliates - Additional Information (details) (USD $)

6 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

1 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

31-May-08

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Western Gas Partners Long Term Incentive Plan [Member]

Western Gas Partners Long Term Incentive Plan [Member]

Western Gas Partners Long Term Incentive Plan [Member]

Western Gas Partners Long Term Incentive Plan [Member]

Western Gas Equity Partners Long Term Incentive Plan [Member]

Western Gas Equity Partners Long Term Incentive Plan [Member]

Western Gas Equity Partners Long Term Incentive Plan [Member]

Western Gas Equity Partners Long Term Incentive Plan [Member]

Independent Director [Member]

Note Receivable From Anadarko [Member]

Note Receivable From Anadarko [Member]

Note Receivable From Anadarko [Member]

Gathering Transportation And Treating [Member]

Gathering Transportation And Treating [Member]

Gathering Transportation And Treating [Member]

Gathering Transportation And Treating [Member]

Processing [Member]

Processing [Member]

Processing [Member]

Processing [Member]

Anadarko Incentive Plans [Member]

Anadarko Incentive Plans [Member]

Anadarko Incentive Plans [Member]

Anadarko Incentive Plans [Member]

Western Gas Partners Long Term Incentive Plan [Member]

Related Party Transaction [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Note receivable - Anadarko

$260,000,000

$260,000,000

[1]

'

'

'

'

'

'

'

'

'

$260,000,000

'

'

'

'

'

'

'

'

'

'

Note receivable, due date

'

'

'

'

'

'

'

'

'

'

'

'

14-May-38

'

'

'

'

'

'

'

'

'

Fixed annual rate for note receivable bearing interest

'

'

'

'

'

'

'

'

'

'

'

6.50%

'

'

'

'

'

'

'

'

'

'

The fair value of the note receivable

'

'

'

'

'

'

'

'

'

'

'

'

336,900,000

296,700,000

'

'

'

'

'

'

'

'

Affiliate throughput percent

'

'

'

'

'

'

'

'

'

'

'

'

'

'

49.00%

56.00%

49.00%

57.00%

58.00%

57.00%

58.00%

58.00%

Phantom units vesting term

'

'

'

'

'3 years

'

'

'

'

'

'1 year

'

'

'

'

'

'

'

'

'

'

'

Equity-based compensation expense

'

'

200,000

200,000

300,000

300,000

900,000

700,000

1,800,000

1,400,000

'

'

'

'

'

'

'

'

'

'

'

'

Partners' capital adjustment

$112,000

'

'

'

'

'

'

'

$1,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

Financial information has been recast to include the financial position and results attributable to the TEFR Interests. See Note 1 and Note 2.

Recovered_Sheet1

Property, Plant and Equipment Table (details) (USD $)

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Jun. 30, 2014

In Thousands, unless otherwise specified

Land [Member]

Land [Member]

Gathering Systems [Member]

Gathering Systems [Member]

Gathering Systems [Member]

Gathering Systems [Member]

Pipelines And Equipment [Member]

Pipelines And Equipment [Member]

Pipelines And Equipment [Member]

Pipelines And Equipment [Member]

Assets Under Construction [Member]

Assets Under Construction [Member]

Other [Member]

Other [Member]

Other [Member]

Other [Member]

Minimum [Member]

Maximum [Member]

Minimum [Member]

Maximum [Member]

Minimum [Member]

Maximum [Member]

Property, Plant and Equipment [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Property, plant and equipment

$4,591,935

$4,239,100

[1]

$2,584

$2,584

$4,123,786

$3,673,008

'

'

$145,799

$146,008

'

'

$304,854

$405,633

$14,912

$11,867

'

'

Accumulated depreciation

936,568

855,845

[1]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net property, plant and equipment

$3,655,367

$3,383,255

[1]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Estimated useful life

'

'

'

'

'

'

'3 years

'47 years

'

'

'15 years

'45 years

'

'

'

'

'3 years

'40 years

[1]

Financial information has been recast to include the financial position and results attributable to the TEFR Interests. See Note 1 and Note 2.

Property_Plant_and_Equipment_A

Property, Plant and Equipment - Additional Information (details) (USD $)	3 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]	'	'	'
Unguaranteed residual value	'	'	$4,600,000
Property, plant and equipment	4,591,935,000	'	4,239,100,000	[1]
Impairment	300,000	1,200,000	'
Natural Gas Processing Plant [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Property, plant and equipment	4,600,000	'	'
Equipment [Member]	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Estimated Fair Value	'	$2,400,000	'
[1]	Financial information has been recast to include the financial position and results attributable to the TEFR Interests. See Note 1 and Note 2.

Components_of_Working_Capital_1

Components of Working Capital - Other Current Assets Table (details) (USD $)	Jun. 30, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Other Current Assets [Line Items]	'		'
Natural gas liquids inventory	$2,188		$2,584
Natural gas imbalance receivables	974		3,605
Prepaid insurance	349		2,123
Other	1,049		1,710
Total other current assets	$4,560	[1]	$10,022	[1],[2]
[1]	Other current assets includes natural gas imbalance receivables from affiliates of $0.2 million and $0.1 million as of June 30, 2014, and December 31, 2013, respectively.
[2]	Financial information has been recast to include the financial position and results attributable to the TEFR Interests. See Note 1 and Note 2.

Components_of_Working_Capital_2

Components of Working Capital - Accrued Liabilities Table (details) (USD $)	Jun. 30, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Accrued Liabilities [Line Items]	'		'
Other accrued liabilities	$81		$218
Accrued interest expense	25,492		18,119
Short-term asset retirement obligations	605		1,966
Short-term remediation and reclamation obligations	562		562
Total accrued liabilities	133,069	[1]	137,011	[1],[2]
Accrued Capital Expenditures [Member]	'		'
Accrued Liabilities [Line Items]	'		'
Other accrued liabilities	77,996		94,750
Accrued Plant Purchases [Member]	'		'
Accrued Liabilities [Line Items]	'		'
Other accrued liabilities	$28,333		$21,396
[1]	Accrued liabilities includes amounts payable to affiliates of zero and $0.1 million as of June 30, 2014, and December 31, 2013, respectively.
[2]	Financial information has been recast to include the financial position and results attributable to the TEFR Interests. See Note 1 and Note 2.

Debt_and_Interest_Expense_Debt

Debt and Interest Expense - Debt Outstanding Table (details) (USD $)	Jun. 30, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'		'
Principal	$2,030,000		$1,420,000
Carrying Value	2,022,876		1,418,169	[1]
Fair Value	2,173,022	[2]	1,422,840	[2]
Revolving Credit Facility [Member]	'		'
Debt Instrument [Line Items]	'		'
Principal	110,000		0
Carrying Value	110,000		0
Fair Value	110,000	[2]	0	[2]
Senior Notes 5 Point 375 Percent Due 2021 [Member]	'		'
Debt Instrument [Line Items]	'		'
Principal	500,000		500,000
Carrying Value	495,439		495,173
Fair Value	566,283	[2]	533,615	[2]
Senior Notes 4 Percent Due 2022 [Member]	'		'
Debt Instrument [Line Items]	'		'
Principal	670,000		670,000
Carrying Value	673,105		673,278
Fair Value	697,141	[2]	641,237	[2]
Senior Notes 2 Point 6 Percent Due 2018 [Member]	'		'
Debt Instrument [Line Items]	'		'
Principal	350,000		250,000
Carrying Value	350,537		249,718
Fair Value	358,515	[2]	247,988	[2]
Senior Notes 5 Point 45 Percent Due 2044 [Member]	'		'
Debt Instrument [Line Items]	'		'
Principal	400,000		0
Carrying Value	393,795		0
Fair Value	$441,083	[2]	$0	[2]
[1]	Financial information has been recast to include the financial position and results attributable to the TEFR Interests. See Note 1 and Note 2.
[2]	Fair value is measured using Level 2 inputs.

Debt_and_Interest_Expense_Debt1

Debt and Interest Expense - Debt Activity Table (details) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014
Debt Instrument [Line Items]	'
Beginning Balance	$1,418,169	[1]
Other	-5,293
Ending Balance	2,022,876
Revolving Credit Facility [Member]	'
Debt Instrument [Line Items]	'
Beginning Balance	0
Borrowings	590,000
Repayments	-480,000
Ending Balance	110,000
Senior Notes 5 Point 45 Percent Due 2044 [Member]	'
Debt Instrument [Line Items]	'
Beginning Balance	0
Borrowings	400,000
Ending Balance	393,795
Senior Notes 2 Point 6 Percent Due 2018 [Member]	'
Debt Instrument [Line Items]	'
Beginning Balance	249,718
Borrowings	100,000
Ending Balance	$350,537
[1]	Financial information has been recast to include the financial position and results attributable to the TEFR Interests. See Note 1 and Note 2.

Debt_and_Interest_Expense_Inte

Debt and Interest Expense - Interest Expense Table (details) (USD $)	3 Months Ended			6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013		Jun. 30, 2014	Jun. 30, 2013
Debt Instruments [Abstract]	'	'		'	'
Interest expense on long-term debt	$21,445	$14,850		$37,580	$28,789
Amortization of debt issuance costs and commitment fees	1,426	1,064		2,692	2,117
Capitalized interest	-2,007	-3,260		-5,447	-6,441
Interest Expense	$20,864	$12,654	[1]	$34,825	$24,465	[1]
[1]	Financial information has been recast to include the financial position and results attributable to the TEFR Interests. See Note 1 and Note 2.

Debt_and_Interest_Expense_Addi

Debt and Interest Expense - Additional Information (details) (USD $)

6 Months Ended

12 Months Ended

1 Months Ended

6 Months Ended

1 Months Ended

6 Months Ended

1 Months Ended

6 Months Ended

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Dec. 31, 2013

Feb. 28, 2014

Mar. 31, 2011

Feb. 28, 2014

Feb. 28, 2014

Feb. 28, 2014

Feb. 28, 2014

Feb. 28, 2014

Feb. 28, 2014

Mar. 31, 2014

Mar. 31, 2014

Jun. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Jun. 30, 2014

Mar. 31, 2014

Jun. 30, 2014

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Percentage Above Federal Funds Effective Rate [Member]

Texas Express And Front Range [Member]

Texas Express And Front Range [Member]

Senior Notes 5 Point 375 Percent Due 2021 [Member]

Senior Notes 4 Percent Due 2022 [Member]

Senior Notes 2 Point 6 Percent Due 2018 [Member]

Senior Notes 2 Point 6 Percent Due 2018 [Member]

Senior Notes 5 Point 45 Percent Due 2044 [Member]

Senior Notes 5 Point 45 Percent Due 2044 [Member]

Alternate Base Rate [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Alternate Base Rate [Member]

Alternate Base Rate [Member]

Alternate Base Rate [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fixed interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5.38%

4.00%

'

2.60%

'

5.45%

Offering percent

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100.86%

'

98.44%

'

Effective interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2.74%

'

5.63%

Underwriting discount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$600,000

'

$3,500,000

'

Debt instrument, maturity date

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1-Jun-21

1-Jul-22

'

15-Aug-18

'

1-Apr-44

Line of credit, expiration date

'

'

26-Feb-19

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Borrowings

1,076,895,000

494,948,000

[1]

'

'

'

'

'

'

'

'

'

'

350,000,000

[2]

350,000,000

'

'

'

'

'

'

Revolving credit facility, maximum borrowing capacity

'

'

'

'

1,200,000,000

800,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revolving credit facility, expandable maximum borrowing capacity

'

'

'

'

1,500,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest rate percent above LIBOR

'

'

'

'

'

'

1.00%

0.98%

0.00%

1.45%

0.45%

0.50%

'

'

'

'

'

'

'

'

Revolving credit facility, interest rate at period end

'

'

1.46%

1.67%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Facility fee

'

'

0.20%

0.25%

'

'

'

0.15%

'

0.30%

'

'

'

'

'

'

'

'

'

'

Outstanding borrowings

'

'

110,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Outstanding letters of credit

'

'

12,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Available borrowing capacity

'

'

$1,100,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

Financial information has been recast to include the financial position and results attributable to the TEFR Interests. See Note 1 and Note 2.

[2]

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 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’s general partner purchased 6,296 general partner units for consideration of $0.4 million to maintain its 2.0% general partner interest in the Partnership.

Commitments_and_Contingencies_

Commitments and Contingencies - Additional Information (details) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'	'	'	'
Committed capital	$58.30	'	$58.30	'
Rent expense associated with office and equipment leases	$0.70	$0.70	$1.50	$1.40