Western Midstream Partners 10-Q 10 Aug 20 2020 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 30, 2020	Aug. 06, 2020
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2020
Document Transition Report	false
Entity Registrant Name	WESTERN MIDSTREAM PARTNERS, LP
Entity File Number	001-35753
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-0967367
Entity Address, Address Line One	9950 Woodloch Forest Drive
Entity Address, City or Town	The Woodlands,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77380
City Area Code	(832)
Local Phone Number	636-1009
Title of 12(b) Security	Common units
Trading Symbol	WES
Security Exchange Name	NYSE
Entity Common Units Outstanding		443,992,499
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Central Index Key	0001423902
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31
Former Address [Member]
Entity Information [Line Items]
Entity Address, Address Line One	1201 Lake Robbins Drive
Entity Address, City or Town	The Woodlands,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77380
WES Operating [Member]
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2020
Document Transition Report	false
Entity Registrant Name	WESTERN MIDSTREAM OPERATING, LP
Entity File Number	001-34046
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-1075808
Entity Address, Address Line One	9950 Woodloch Forest Drive
Entity Address, City or Town	The Woodlands,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77380
City Area Code	(832)
Local Phone Number	636-1009
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Central Index Key	0001414475
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31
WES Operating [Member] | Former Address [Member]
Entity Information [Line Items]
Entity Address, Address Line One	1201 Lake Robbins Drive
Entity Address, City or Town	The Woodlands,
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77380

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues and Other
Revenues and other	[1]	$ 671,755,000	$ 685,054,000	$ 1,446,068,000	$ 1,356,937,000
Equity income, net – related parties		54,415,000	63,598,000	115,762,000	121,590,000
Operating expenses
Cost of product		18,602,000	122,877,000	121,872,000	236,940,000
Operation and maintenance		145,186,000	148,431,000	304,377,000	291,260,000
General and administrative		36,423,000	30,027,000	76,888,000	52,871,000
Property and other taxes		19,395,000	14,282,000	37,871,000	30,567,000
Depreciation and amortization		119,805,000	121,117,000	252,124,000	235,063,000
Long-lived asset impairments		10,150,000	797,000	165,935,000	1,187,000
Goodwill impairment		0	0	441,017,000	0
Total operating expenses	[2]	349,561,000	437,531,000	1,400,084,000	847,888,000
Gain (loss) on divestiture and other, net		(2,843,000)	(1,061,000)	(2,883,000)	(1,651,000)
Operating income (loss)		373,766,000	310,060,000	158,863,000	628,988,000
Interest income – Anadarko note receivable		4,225,000	4,225,000	8,450,000	8,450,000
Interest expense		(94,654,000)	(79,472,000)	(183,240,000)	(145,348,000)
Gain (loss) on early extinguishment of debt		1,395,000	0	8,740,000	0
Other income (expense), net	[3]	1,653,000	(58,477,000)	(108,000)	(93,683,000)
Income (loss) before income taxes		286,385,000	176,336,000	(7,295,000)	398,407,000
Income tax expense (benefit)		5,044,000	1,278,000	764,000	11,370,000
Net income (loss)		281,341,000	175,058,000	(8,059,000)	387,037,000
Net income (loss) attributable to noncontrolling interests		8,304,000	5,464,000	(24,569,000)	98,783,000
Net income (loss) attributable to Western Midstream Partners, LP		273,037,000	169,594,000	16,510,000	288,254,000
Limited partners' interest in net income (loss):
Net income (loss) attributable to Western Midstream Partners, LP		273,037,000	169,594,000	16,510,000	288,254,000
Pre-acquisition net (income) loss allocated to Anadarko		0	(163,000)	0	(29,279,000)
General partner interest in net (income) loss		(5,461,000)	0	(330,000)	0
Limited partners' interest in net income (loss)	[4]	267,576,000	169,431,000	16,180,000	258,975,000
Service Revenues - Fee Based [Member]
Revenues and Other
Revenues and other		642,628,000	593,544,000	1,344,024,000	1,173,518,000
Service Revenues - Product Based [Member]
Revenues and Other
Revenues and other		7,000,000	16,675,000	22,921,000	36,054,000
Product Sales [Member]
Revenues and Other
Revenues and other		21,736,000	74,469,000	78,385,000	146,602,000
Other [Member]
Revenues and Other
Revenues and other		391,000	366,000	738,000	763,000
Related Parties [Member]
Revenues and Other
Revenues and other		473,442,000	385,184,000	955,827,000	763,621,000
Operating expenses
Cost of product		5,967,000	68,225,000	83,870,000	124,397,000
Operation and maintenance		1,516,000	32,318,000	34,357,000	71,459,000
General and administrative		10,994,000	26,892,000	32,849,000	45,786,000
Total operating expenses		18,477,000	127,435,000	151,076,000	241,642,000
Interest expense		0	(20,000)	(43,000)	(1,853,000)
Related Parties [Member] | Service Revenues - Fee Based [Member]
Revenues and Other
Revenues and other		460,138,000	343,484,000	907,921,000	670,126,000
Related Parties [Member] | Service Revenues - Product Based [Member]
Revenues and Other
Revenues and other		1,168,000	634,000	4,146,000	1,986,000
Related Parties [Member] | Product Sales [Member]
Revenues and Other
Revenues and other		$ 12,136,000	$ 41,066,000	$ 43,760,000	$ 91,509,000
Limited Partner [Member]
Limited partners' interest in net income (loss):
Net income (loss) per common unit - basic and diluted	[4]	$ 0.60	$ 0.37	$ 0.04	$ 0.69
Weighted-average common units outstanding - basic and diluted		443,973	453,000	443,972	376,702
[1]	Total revenues and other includes related-party amounts of $473.4 million and $955.8 million for the three and six months ended June 30, 2020, respectively, and $385.2 million and $763.6 million for the three and six months ended June 30, 2019, respectively. See Note 6 .
[2]	Total operating expenses includes related-party amounts of $18.5 million and $151.1 million for the three and six months ended June 30, 2020, respectively, and $127.4 million and $241.6 million for the three and six months ended June 30, 2019, respectively. See Note 6 .
[3]	Other income (expense), net includes losses associated with the interest-rate swap agreements for the three and six months ended June 30, 2019. See Note 11.
[4]	See Note 5.

Consolidated Statements of Op_2

Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Total revenues and other	[1]	$ 671,755	$ 685,054	$ 1,446,068	$ 1,356,937
Total operating expenses	[2]	349,561	437,531	1,400,084	847,888
Related Parties [Member]
Total revenues and other		473,442	385,184	955,827	763,621
Total operating expenses		$ 18,477	$ 127,435	$ 151,076	$ 241,642
[1]	Total revenues and other includes related-party amounts of $473.4 million and $955.8 million for the three and six months ended June 30, 2020, respectively, and $385.2 million and $763.6 million for the three and six months ended June 30, 2019, respectively. See Note 6 .
[2]	Total operating expenses includes related-party amounts of $18.5 million and $151.1 million for the three and six months ended June 30, 2020, respectively, and $127.4 million and $241.6 million for the three and six months ended June 30, 2019, respectively. See Note 6 .

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands		Jun. 30, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents		$ 59,738	$ 99,962
Accounts receivable, net		460,318	260,512
Other current assets		39,107	41,938
Total current assets		559,163	402,412
Property, plant, and equipment
Cost		12,599,722	12,355,671
Less accumulated depreciation		3,685,006	3,290,740
Net property, plant, and equipment		8,914,716	9,064,931
Goodwill		4,783	445,800
Other intangible assets		792,557	809,391
Equity investments		1,280,047	1,285,717
Other assets	[1]	142,496	78,202
Total assets	[2]	11,953,243	12,346,453
Current liabilities
Accounts and imbalance payables		181,563	293,128
Short-term debt		438,619	7,873
Accrued ad valorem taxes		53,639	35,160
Accrued liabilities		217,225	149,793
Total current liabilities		891,046	485,954
Long-term debt		7,544,396	7,951,565
Long-term liabilities
Long-term debt		7,544,396	7,951,565
Deferred income taxes		19,698	18,899
Asset retirement obligations		327,971	336,396
Other liabilities		234,615	208,346
Total long-term liabilities		8,126,680	8,515,206
Total liabilities	[3]	9,017,726	9,001,160
Equity and partners' capital
Common units (443,992,499 and 443,971,409 units issued and outstanding at June 30, 2020, and December 31, 2019, respectively)		2,820,327	3,209,947
General partner units (9,060,641 units issued and outstanding at June 30, 2020, and December 31, 2019) (4)	[4]	(22,347)	(14,224)
Total partners' capital		2,797,980	3,195,723
Noncontrolling interests		137,537	149,570
Total equity and partners' capital		2,935,517	3,345,293
Total liabilities, equity, and partners' capital		$ 11,953,243	$ 12,346,453
Common units issued		443,992,499	443,971,409
Common units outstanding		443,992,499	443,971,409
General partner units issued		9,060,641	9,060,641
General partner units outstanding		9,060,641	9,060,641
Related Parties [Member]
Current assets
Accounts receivable, net		$ 325,349	$ 113,345
Other current assets		13,019	4,982
Anadarko note receivable		259,481	260,000
Property, plant, and equipment
Other assets		59,302	60,221
Total assets		1,937,198	1,724,265
Current liabilities
Accounts and imbalance payables		655	0
Accrued liabilities		2,513	3,087
Long-term liabilities
Other liabilities		119,132	97,800
Total liabilities		$ 122,300	$ 108,760
[1]	Other assets includes $3.2 million and $4.5 million of NGLs line-fill inventory as of June 30, 2020, and December 31, 2019, respectively. Other assets also includes $62.6 million of materials and supplies inventory as of June 30, 2020. See Note 1 .
[2]	Total assets includes related-party amounts of $1.9 billion and $1.7 billion as of June 30, 2020, and December 31, 2019, respectively, which includes related-party Accounts receivable, net of $325.3 million and $113.3 million as of June 30, 2020, and December 31, 2019, respectively. See Note 6 .
[3]	Total liabilities includes related-party amounts of $122.3 million and $108.8 million as of June 30, 2020, and December 31, 2019, respectively. See Note 6 .
[4]	See Note 1 .

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands		Jun. 30, 2020	Dec. 31, 2019
Materials and supplies inventory		$ 62,600
Total assets	[1]	11,953,243	$ 12,346,453
Accounts receivable, net		460,318	260,512
Total liabilities	[2]	9,017,726	9,001,160
Related Parties [Member]
Total assets		1,937,198	1,724,265
Accounts receivable, net		325,349	113,345
Total liabilities		122,300	108,760
Natural-Gas Liquids [Member]
NGLs line-fill inventory		$ 3,200	$ 4,500
[1]	Total assets includes related-party amounts of $1.9 billion and $1.7 billion as of June 30, 2020, and December 31, 2019, respectively, which includes related-party Accounts receivable, net of $325.3 million and $113.3 million as of June 30, 2020, and December 31, 2019, respectively. See Note 6 .
[2]	Total liabilities includes related-party amounts of $122.3 million and $108.8 million as of June 30, 2020, and December 31, 2019, respectively. See Note 6 .

Consolidated Statements of Equi

Consolidated Statements of Equity and Partners' Capital - USD ($) $ in Thousands		Total	Chipeta [Member]	WES Operating [Member]	Net Investment by Anadarko [Member]	Common Units [Member]	General Partner [Member]	Noncontrolling Interests [Member]	Noncontrolling Interests [Member]Chipeta [Member]	Noncontrolling Interests [Member]WES Operating [Member]
Balance at Dec. 31, 2018		$ 4,892,683			$ 1,388,018	$ 951,888		$ 2,552,777
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)		211,979			29,116	89,544		93,319
Distributions to noncontrolling interest owners			$ (1,935)	$ (100,999)					$ (1,935)	$ (100,999)
Distributions to Partnership unitholders		(131,910)				(131,910)
Acquisitions from related parties	[1]	(2,007,501)			(2,141,827)	106,856		27,470
Contributions of equity-based compensation from Anadarko/Occidental		1,840				1,840
Net pre-acquisition contributions from (distributions to) related parties		451,591			451,591
Cumulative impact of the Merger transactions	[2]	0				3,169,800		(3,169,800)
Above-market component of swap agreements with Anadarko	[3]	7,407				7,407
WES Operating equity transactions, net	[4]	0				(752,796)		752,796
Adjustments of net deferred tax liabilities		268,727			273,102	(4,375)
Other		(341)				(332)		(9)
Balance at Mar. 31, 2019		3,591,541			0	3,437,922		153,619
Balance at Dec. 31, 2018		4,892,683			1,388,018	951,888		2,552,777
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)		387,037
Balance at Jun. 30, 2019		3,491,210			0	3,338,646		152,564
Balance at Mar. 31, 2019		3,591,541			0	3,437,922		153,619
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)		175,058			163	169,431		5,464
Distributions to noncontrolling interest owners			(1,858)	(5,667)					(1,858)	(5,667)
Distributions to Partnership unitholders		(276,324)				(276,324)
Acquisitions from related parties	[1]	0			(5,510)	4,493		1,017
Contributions of equity-based compensation from Anadarko/Occidental		2,768				2,768
Net pre-acquisition contributions from (distributions to) related parties		5,347			5,347
Other		345				356		(11)
Balance at Jun. 30, 2019		3,491,210			$ 0	3,338,646		152,564
Balance at Dec. 31, 2019		3,345,293				3,209,947	$ (14,224)	149,570
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)		(289,400)				(251,396)	(5,131)	(32,873)
Distributions to noncontrolling interest owners			(1,738)	(5,807)					(1,738)	(5,807)
Distributions to Partnership unitholders		(281,786)				(276,151)	(5,635)
Acquisitions from related parties		0				(3,987)		3,987
Contributions of equity-based compensation from Anadarko/Occidental		4,105				4,105
Equity-based compensation expense		1,129				1,129
Net contributions from (distributions to) related parties	[5]	20,489				489		20,000
Balance at Mar. 31, 2020		2,792,285				2,684,136	(24,990)	133,139
Balance at Dec. 31, 2019		3,345,293				3,209,947	(14,224)	149,570
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)		(8,059)
Balance at Jun. 30, 2020		2,935,517				2,820,327	(22,347)	137,537
Balance at Mar. 31, 2020		2,792,285				2,684,136	(24,990)	133,139
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)		281,341				267,576	5,461	8,304
Distributions to noncontrolling interest owners			$ (1,037)	$ (2,869)					$ (1,037)	$ (2,869)
Distributions to Partnership unitholders		(140,893)				(138,075)	(2,818)
Contributions of equity-based compensation from Anadarko/Occidental		3,562				3,562
Equity-based compensation expense		2,115				2,115
Net contributions from (distributions to) related parties		1,343				1,343
Other		(330)				(330)
Balance at Jun. 30, 2020		$ 2,935,517				$ 2,820,327	$ (22,347)	$ 137,537
[1]	The amounts allocated to common unitholders and noncontrolling interests represent a non-cash investing activity related to the assets and liabilities assumed in the AMA acquisition. See Note 3 .
[2]	See Note 1 .
[3]	See Note 6 .
[4]	For the three months ended March 31, 2019, the $752.8 million decrease to partners’ capital, together with net income (loss) attributable to Western Midstream Partners, LP, totaled $(634.1) million.
[5]	See December 2019 Agreements—Services, Secondment, and Employee Transfer Agreement within Note 1.

Consolidated Statements of Eq_2

Consolidated Statements of Equity and Partners' Capital (Parenthetical) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
WES Operating equity transactions, net	$ 0	[1]
Combined change in Partners' Capital from WES Operating equity transactions, net and net income (loss) attributable to Western Midstream Partners, LP	(634,100)
Common Units [Member]
WES Operating equity transactions, net	$ (752,796)	[1]
[1]	For the three months ended March 31, 2019, the $752.8 million decrease to partners’ capital, together with net income (loss) attributable to Western Midstream Partners, LP, totaled $(634.1) million.

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities
Net income (loss)		$ (8,059)	$ 387,037
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization		252,124	235,063
Long-lived asset impairments		165,935	1,187
Goodwill impairment		441,017	0
Non-cash equity-based compensation expense		10,911	5,493
Deferred income taxes		799	4,885
Accretion and amortization of long-term obligations, net		4,297	2,848
Equity income, net – related parties		(115,762)	(121,590)
Distributions from equity-investment earnings – related parties		124,156	115,483
(Gain) loss on divestiture and other, net		2,883	1,651
(Gain) loss on early extinguishment of debt		(8,740)	0
(Gain) loss on interest-rate swaps		0	94,585
Cash paid to settle interest-rate swaps		(12,763)	0
Other		710	169
Changes in assets and liabilities:
(Increase) decrease in accounts receivable, net		(200,136)	2,668
Increase (decrease) in accounts and imbalance payables and accrued liabilities, net		72,323	(81,198)
Change in other items, net		9,304	38,250
Net cash provided by operating activities		738,999	686,531
Cash flows from investing activities
Capital expenditures		(313,065)	(704,425)
Contributions to equity investments - related parties		(16,064)	(77,333)
Distributions from equity investments in excess of cumulative earnings – related parties		13,340	17,052
Proceeds from the sale of assets to third parties		0	342
Other		(39,212)	0
Net cash used in investing activities		(355,001)	(2,865,168)
Cash flows from financing activities
Borrowings, net of debt issuance costs	[1]	3,586,173	2,710,750
Repayments of debt	[2]	(3,583,149)	(467,595)
Increase (decrease) in outstanding checks		(4,686)	(5,662)
Registration expenses related to the issuance of Partnership common units		0	(855)
Distributions to Partnership unitholders	[3]	(422,679)	(408,234)
Net contributions from (distributions to) related parties		21,832	456,938
Above-market component of swap agreements with Anadarko	[3]	0	7,407
Finance lease payments	[4]	(10,262)	0
Net cash provided by (used in) financing activities		(424,222)	2,182,290
Net increase (decrease) in cash and cash equivalents		(40,224)	3,653
Cash and cash equivalents at beginning of period		99,962	92,142
Cash and cash equivalents at end of period		59,738	95,795
Supplemental disclosures
Interest paid, net of capitalized interest		163,362	137,686
Taxes paid (reimbursements received)		(384)	96
Accrued capital expenditures		43,191	141,094
Chipeta [Member]
Cash flows from financing activities
Distributions to Chipeta noncontrolling interest owner		(2,775)	(3,793)
WES Operating [Member]
Cash flows from financing activities
Distributions to noncontrolling interest owners of WES Operating		(8,676)	(106,666)
Related Parties [Member]
Cash flows from investing activities
Acquisitions		0	(2,007,501)
Cash flows from financing activities
Borrowings, net of debt issuance costs			11,000
Repayments of debt			(439,600)
Distributions to Partnership unitholders		(225,914)	(255,885)
Finance lease payments		(6,382)	0
Related Parties [Member] | WES Operating [Member]
Cash flows from financing activities
Distributions to Partnership unitholders		(8,676)	(8,210)
Third Parties [Member]
Cash flows from investing activities
Acquisitions		$ 0	$ (93,303)
[1]	For the six months ended June 30, 2019, includes an $11.0 million borrowing under the APCWH Note Payable.
[2]	For the six months ended June 30, 2019, includes a $439.6 million repayment to settle the APCWH Note Payable. See Note 6 .
[3]	See Note 6 .
[4]	For the six months ended June 30, 2020, includes related-party payments of $6.4 million.

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019
Borrowings, net of debt issuance costs	[1]	$ 3,586,173	$ 2,710,750
Repayments of debt	[2]	3,583,149	467,595
Finance lease payments	[3]	10,262	0
Related Parties [Member]
Borrowings, net of debt issuance costs			11,000
Repayments of debt			439,600
Finance lease payments		$ 6,382	$ 0
[1]	For the six months ended June 30, 2019, includes an $11.0 million borrowing under the APCWH Note Payable.
[2]	For the six months ended June 30, 2019, includes a $439.6 million repayment to settle the APCWH Note Payable. See Note 6 .
[3]	For the six months ended June 30, 2020, includes related-party payments of $6.4 million.

Consolidated Statements of Op_3

Consolidated Statements of Operations - WES Operating - USD ($)		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues and Other
Revenues and other	[1]	$ 671,755,000	$ 685,054,000	$ 1,446,068,000	$ 1,356,937,000
Equity income, net – related parties		54,415,000	63,598,000	115,762,000	121,590,000
Operating expenses
Cost of product		18,602,000	122,877,000	121,872,000	236,940,000
Operation and maintenance		145,186,000	148,431,000	304,377,000	291,260,000
General and administrative		36,423,000	30,027,000	76,888,000	52,871,000
Property and other taxes		19,395,000	14,282,000	37,871,000	30,567,000
Depreciation and amortization		119,805,000	121,117,000	252,124,000	235,063,000
Long-lived asset impairments		10,150,000	797,000	165,935,000	1,187,000
Goodwill impairment		0	0	441,017,000	0
Total operating expenses	[2]	349,561,000	437,531,000	1,400,084,000	847,888,000
Gain (loss) on divestiture and other, net		(2,843,000)	(1,061,000)	(2,883,000)	(1,651,000)
Operating income (loss)		373,766,000	310,060,000	158,863,000	628,988,000
Interest income – Anadarko note receivable		4,225,000	4,225,000	8,450,000	8,450,000
Interest expense		(94,654,000)	(79,472,000)	(183,240,000)	(145,348,000)
Gain (loss) on early extinguishment of debt		1,395,000	0	8,740,000	0
Other income (expense), net	[3]	1,653,000	(58,477,000)	(108,000)	(93,683,000)
Income (loss) before income taxes		286,385,000	176,336,000	(7,295,000)	398,407,000
Income tax expense (benefit)		5,044,000	1,278,000	764,000	11,370,000
Net income (loss)		281,341,000	175,058,000	(8,059,000)	387,037,000
Net income (loss) attributable to noncontrolling interest		8,304,000	5,464,000	(24,569,000)	98,783,000
Net income (loss) attributable to Western Midstream Operating, LP		273,037,000	169,594,000	16,510,000	288,254,000
Limited partners' interest in net income (loss):
Net income (loss) attributable to Western Midstream Operating, LP		273,037,000	169,594,000	16,510,000	288,254,000
Pre-acquisition net (income) loss allocated to Anadarko		0	(163,000)	0	(29,279,000)
Limited partners' interest in net income (loss)	[4]	267,576,000	169,431,000	16,180,000	258,975,000
Service Revenues - Fee Based [Member]
Revenues and Other
Revenues and other		642,628,000	593,544,000	1,344,024,000	1,173,518,000
Service Revenues - Product Based [Member]
Revenues and Other
Revenues and other		7,000,000	16,675,000	22,921,000	36,054,000
Product Sales [Member]
Revenues and Other
Revenues and other		21,736,000	74,469,000	78,385,000	146,602,000
Other [Member]
Revenues and Other
Revenues and other		391,000	366,000	738,000	763,000
Related Parties [Member]
Revenues and Other
Revenues and other		473,442,000	385,184,000	955,827,000	763,621,000
Operating expenses
Cost of product		5,967,000	68,225,000	83,870,000	124,397,000
Operation and maintenance		1,516,000	32,318,000	34,357,000	71,459,000
General and administrative		10,994,000	26,892,000	32,849,000	45,786,000
Total operating expenses		18,477,000	127,435,000	151,076,000	241,642,000
Interest expense		0	(20,000)	(43,000)	(1,853,000)
Related Parties [Member] | Service Revenues - Fee Based [Member]
Revenues and Other
Revenues and other		460,138,000	343,484,000	907,921,000	670,126,000
Related Parties [Member] | Service Revenues - Product Based [Member]
Revenues and Other
Revenues and other		1,168,000	634,000	4,146,000	1,986,000
Related Parties [Member] | Product Sales [Member]
Revenues and Other
Revenues and other		12,136,000	41,066,000	43,760,000	91,509,000
WES Operating [Member]
Revenues and Other
Revenues and other	[5]	671,755,000	685,054,000	1,446,068,000	1,356,937,000
Equity income, net – related parties		54,415,000	63,598,000	115,762,000	121,590,000
Operating expenses
Cost of product		18,602,000	122,877,000	121,872,000	236,940,000
Operation and maintenance		145,186,000	148,431,000	304,377,000	291,260,000
General and administrative		35,242,000	28,101,000	74,300,000	48,661,000
Property and other taxes		19,395,000	14,282,000	37,871,000	30,567,000
Depreciation and amortization		119,805,000	121,117,000	252,124,000	235,063,000
Long-lived asset impairments		10,150,000	797,000	165,935,000	1,187,000
Goodwill impairment		0	0	441,017,000	0
Total operating expenses	[6]	348,380,000	435,605,000	1,397,496,000	843,678,000
Gain (loss) on divestiture and other, net		(2,843,000)	(1,061,000)	(2,883,000)	(1,651,000)
Operating income (loss)		374,947,000	311,986,000	161,451,000	633,198,000
Interest income – Anadarko note receivable		4,225,000	4,225,000	8,450,000	8,450,000
Interest expense		(94,654,000)	(79,472,000)	(183,240,000)	(145,103,000)
Gain (loss) on early extinguishment of debt		1,395,000	0	8,740,000	0
Other income (expense), net	[7]	1,651,000	(58,482,000)	(112,000)	(93,746,000)
Income (loss) before income taxes		287,564,000	178,257,000	(4,711,000)	402,799,000
Income tax expense (benefit)		5,044,000	1,278,000	764,000	11,370,000
Net income (loss)		282,520,000	176,979,000	(5,475,000)	391,429,000
Net income (loss) attributable to noncontrolling interest		2,706,000	1,967,000	(24,959,000)	3,821,000
Net income (loss) attributable to Western Midstream Operating, LP		279,814,000	175,012,000	19,484,000	387,608,000
Limited partners' interest in net income (loss):
Net income (loss) attributable to Western Midstream Operating, LP		279,814,000	175,012,000	19,484,000	387,608,000
Pre-acquisition net (income) loss allocated to Anadarko		0	(163,000)	0	(29,279,000)
WES Operating [Member] | Common and Class C Units [Member]
Limited partners' interest in net income (loss):
Limited partners' interest in net income (loss)	[8]	279,814,000	174,849,000	19,484,000	358,329,000
WES Operating [Member] | Service Revenues - Fee Based [Member]
Revenues and Other
Revenues and other		642,628,000	593,544,000	1,344,024,000	1,173,518,000
WES Operating [Member] | Service Revenues - Product Based [Member]
Revenues and Other
Revenues and other		7,000,000	16,675,000	22,921,000	36,054,000
WES Operating [Member] | Product Sales [Member]
Revenues and Other
Revenues and other		21,736,000	74,469,000	78,385,000	146,602,000
WES Operating [Member] | Other [Member]
Revenues and Other
Revenues and other		391,000	366,000	738,000	763,000
WES Operating [Member] | Related Parties [Member]
Revenues and Other
Revenues and other		473,400,000	385,200,000	955,800,000	763,600,000
Operating expenses
General and administrative		11,168,000	26,380,000	32,906,000	44,878,000
Total operating expenses		$ 18,700,000	$ 126,900,000	$ 151,100,000	$ 240,700,000
[1]	Total revenues and other includes related-party amounts of $473.4 million and $955.8 million for the three and six months ended June 30, 2020, respectively, and $385.2 million and $763.6 million for the three and six months ended June 30, 2019, respectively. See Note 6 .
[2]	Total operating expenses includes related-party amounts of $18.5 million and $151.1 million for the three and six months ended June 30, 2020, respectively, and $127.4 million and $241.6 million for the three and six months ended June 30, 2019, respectively. See Note 6 .
[3]	Other income (expense), net includes losses associated with the interest-rate swap agreements for the three and six months ended June 30, 2019. See Note 11.
[4]	See Note 5.
[5]	Total revenues and other includes related-party amounts of $473.4 million and $955.8 million for the three and six months ended June 30, 2020, respectively, and $385.2 million and $763.6 million for the three and six months ended June 30, 2019, respectively. See Note 6 .
[6]	Total operating expenses includes related-party amounts of $18.7 million and $151.1 million for the three and six months ended June 30, 2020, respectively, and $126.9 million and $240.7 million for the three and six months ended June 30, 2019, respectively. See Note 6 .
[7]	Other income (expense), net includes losses associated with the interest-rate swap agreements for the three and six months ended June 30, 2019. See Note 11.
[8]	See Note 5.

Consolidated Statements of Op_4

Consolidated Statements of Operations - WES Operating (Parenthetical) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Total revenues and other	[1]	$ 671,755	$ 685,054	$ 1,446,068	$ 1,356,937
Total operating expenses	[2]	349,561	437,531	1,400,084	847,888
Related Parties [Member]
Total revenues and other		473,442	385,184	955,827	763,621
Total operating expenses		18,477	127,435	151,076	241,642
WES Operating [Member]
Total revenues and other	[3]	671,755	685,054	1,446,068	1,356,937
Total operating expenses	[4]	348,380	435,605	1,397,496	843,678
WES Operating [Member] | Related Parties [Member]
Total revenues and other		473,400	385,200	955,800	763,600
Total operating expenses		$ 18,700	$ 126,900	$ 151,100	$ 240,700
[1]	Total revenues and other includes related-party amounts of $473.4 million and $955.8 million for the three and six months ended June 30, 2020, respectively, and $385.2 million and $763.6 million for the three and six months ended June 30, 2019, respectively. See Note 6 .
[2]	Total operating expenses includes related-party amounts of $18.5 million and $151.1 million for the three and six months ended June 30, 2020, respectively, and $127.4 million and $241.6 million for the three and six months ended June 30, 2019, respectively. See Note 6 .
[3]	Total revenues and other includes related-party amounts of $473.4 million and $955.8 million for the three and six months ended June 30, 2020, respectively, and $385.2 million and $763.6 million for the three and six months ended June 30, 2019, respectively. See Note 6 .
[4]	Total operating expenses includes related-party amounts of $18.7 million and $151.1 million for the three and six months ended June 30, 2020, respectively, and $126.9 million and $240.7 million for the three and six months ended June 30, 2019, respectively. See Note 6 .

Consolidated Balance Sheets - W

Consolidated Balance Sheets - WES Operating - USD ($) $ in Thousands		Jun. 30, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents		$ 59,738	$ 99,962
Accounts receivable, net		460,318	260,512
Other current assets		39,107	41,938
Total current assets		559,163	402,412
Property, plant, and equipment
Cost		12,599,722	12,355,671
Less accumulated depreciation		3,685,006	3,290,740
Net property, plant, and equipment		8,914,716	9,064,931
Goodwill		4,783	445,800
Other intangible assets		792,557	809,391
Equity investments		1,280,047	1,285,717
Other assets	[1]	142,496	78,202
Total assets	[2]	11,953,243	12,346,453
Current liabilities
Accounts and imbalance payables		181,563	293,128
Short-term debt		438,619	7,873
Accrued ad valorem taxes		53,639	35,160
Accrued liabilities		217,225	149,793
Total current liabilities		891,046	485,954
Long-term liabilities
Long-term debt		7,544,396	7,951,565
Deferred income taxes		19,698	18,899
Asset retirement obligations		327,971	336,396
Other liabilities		234,615	208,346
Total long-term liabilities		8,126,680	8,515,206
Total liabilities	[3]	9,017,726	9,001,160
Equity and partners' capital
Common units (318,675,578 units issued and outstanding at June 30, 2020, and December 31, 2019)		2,820,327	3,209,947
Total partners' capital		2,797,980	3,195,723
Noncontrolling interest		137,537	149,570
Total equity and partners' capital		2,935,517	3,345,293
Total liabilities, equity, and partners' capital		$ 11,953,243	$ 12,346,453
Common units issued		443,992,499	443,971,409
Common units outstanding		443,992,499	443,971,409
Related Parties [Member]
Current assets
Accounts receivable, net		$ 325,349	$ 113,345
Other current assets		13,019	4,982
Anadarko note receivable		259,481	260,000
Property, plant, and equipment
Other assets		59,302	60,221
Total assets		1,937,198	1,724,265
Current liabilities
Accounts and imbalance payables		655	0
Accrued liabilities		2,513	3,087
Long-term liabilities
Other liabilities		119,132	97,800
Total liabilities		122,300	108,760
WES Operating [Member]
Current assets
Cash and cash equivalents		57,445	98,122
Accounts receivable, net		434,270	260,748
Other current assets		37,725	39,914
Total current assets		529,440	398,784
Property, plant, and equipment
Cost		12,599,722	12,355,671
Less accumulated depreciation		3,685,006	3,290,740
Net property, plant, and equipment		8,914,716	9,064,931
Goodwill		4,783	445,800
Other intangible assets		792,557	809,391
Equity investments		1,280,047	1,285,717
Other assets	[4]	142,496	78,202
Total assets	[5]	11,923,520	12,342,825
Current liabilities
Accounts and imbalance payables		181,314	293,128
Short-term debt		438,619	7,873
Accrued ad valorem taxes		53,639	35,160
Accrued liabilities		193,918	149,639
Total current liabilities		867,490	485,800
Long-term liabilities
Long-term debt		7,544,396	7,951,565
Deferred income taxes		19,698	18,899
Asset retirement obligations		327,971	336,396
Other liabilities		234,615	208,346
Total long-term liabilities		8,126,680	8,515,206
Total liabilities	[6]	8,994,170	9,001,006
Equity and partners' capital
Total partners' capital		2,897,898	3,286,620
Noncontrolling interest		31,452	55,199
Total equity and partners' capital		2,929,350	3,341,819
Total liabilities, equity, and partners' capital		11,923,520	12,342,825
WES Operating [Member] | Common Units [Member]
Equity and partners' capital
Common units (318,675,578 units issued and outstanding at June 30, 2020, and December 31, 2019)		$ 2,897,898	$ 3,286,620
Common units issued		318,675,578	318,675,578
Common units outstanding		318,675,578	318,675,578
WES Operating [Member] | Related Parties [Member]
Current assets
Accounts receivable, net		$ 299,332	$ 113,581
Anadarko note receivable		259,481	260,000
Property, plant, and equipment
Total assets		1,900,000	1,700,000
Long-term liabilities
Total liabilities		$ 122,300	$ 108,800
[1]	Other assets includes $3.2 million and $4.5 million of NGLs line-fill inventory as of June 30, 2020, and December 31, 2019, respectively. Other assets also includes $62.6 million of materials and supplies inventory as of June 30, 2020. See Note 1 .
[2]	Total assets includes related-party amounts of $1.9 billion and $1.7 billion as of June 30, 2020, and December 31, 2019, respectively, which includes related-party Accounts receivable, net of $325.3 million and $113.3 million as of June 30, 2020, and December 31, 2019, respectively. See Note 6 .
[3]	Total liabilities includes related-party amounts of $122.3 million and $108.8 million as of June 30, 2020, and December 31, 2019, respectively. See Note 6 .
[4]	Other assets includes $3.2 million and $4.5 million of NGLs line-fill inventory as of June 30, 2020, and December 31, 2019, respectively. Other assets also includes $62.6 million of materials and supplies inventory as of June 30, 2020. See Note 1 .
[5]	Total assets includes related-party amounts of $1.9 billion and $1.7 billion as of June 30, 2020, and December 31, 2019, respectively, which includes related-party Accounts receivable, net of $299.3 million and $113.6 million as of June 30, 2020, and December 31, 2019, respectively. See Note 6 .
[6]	Total liabilities includes related-party amounts of $122.3 million and $108.8 million as of June 30, 2020, and December 31, 2019, respectively. See Note 6

Consolidated Balance Sheets -_2

Consolidated Balance Sheets - WES Operating (Parenthetical) - USD ($) $ in Thousands		Jun. 30, 2020	Dec. 31, 2019
Materials and supplies inventory		$ 62,600
Total assets	[1]	11,953,243	$ 12,346,453
Accounts receivable, net		460,318	260,512
Total liabilities	[2]	9,017,726	9,001,160
Related Parties [Member]
Total assets		1,937,198	1,724,265
Accounts receivable, net		325,349	113,345
Total liabilities		122,300	108,760
Natural-Gas Liquids [Member]
NGLs line-fill inventory		3,200	4,500
WES Operating [Member]
Materials and supplies inventory		62,600
Total assets	[3]	11,923,520	12,342,825
Accounts receivable, net		434,270	260,748
Total liabilities	[4]	8,994,170	9,001,006
WES Operating [Member] | Related Parties [Member]
Total assets		1,900,000	1,700,000
Accounts receivable, net		299,332	113,581
Total liabilities		122,300	108,800
WES Operating [Member] | Natural-Gas Liquids [Member]
NGLs line-fill inventory		$ 3,200	$ 4,500
[1]	Total assets includes related-party amounts of $1.9 billion and $1.7 billion as of June 30, 2020, and December 31, 2019, respectively, which includes related-party Accounts receivable, net of $325.3 million and $113.3 million as of June 30, 2020, and December 31, 2019, respectively. See Note 6 .
[2]	Total liabilities includes related-party amounts of $122.3 million and $108.8 million as of June 30, 2020, and December 31, 2019, respectively. See Note 6 .
[3]	Total assets includes related-party amounts of $1.9 billion and $1.7 billion as of June 30, 2020, and December 31, 2019, respectively, which includes related-party Accounts receivable, net of $299.3 million and $113.6 million as of June 30, 2020, and December 31, 2019, respectively. See Note 6 .
[4]	Total liabilities includes related-party amounts of $122.3 million and $108.8 million as of June 30, 2020, and December 31, 2019, respectively. See Note 6

Consolidated Statements of Eq_3

Consolidated Statements of Equity and Partners' Capital - WES Operating - USD ($) $ in Thousands	Total		Chipeta [Member]	Net Investment by Anadarko [Member]		Common Units [Member]		General Partner [Member]	Noncontrolling Interest [Member]		Noncontrolling Interest [Member]Chipeta [Member]	WES Operating [Member]		WES Operating [Member]Chipeta [Member]	WES Operating [Member]Net Investment by Anadarko [Member]		WES Operating [Member]Common Units [Member]		WES Operating [Member]Class C Units [Member]		WES Operating [Member]General Partner [Member]		WES Operating [Member]Noncontrolling Interest [Member]	WES Operating [Member]Noncontrolling Interest [Member]Chipeta [Member]
Balance at Dec. 31, 2018	$ 4,892,683			$ 1,388,018		$ 951,888			$ 2,552,777			$ 4,919,597			$ 1,388,018		$ 2,475,540		$ 791,410		$ 206,862		$ 57,767
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)	211,979			29,116		89,544			93,319			214,450			29,116		170,847		10,636		1,997		1,854
Distributions to noncontrolling interest owners			$ (1,935)								$ (1,935)			$ (1,935)										$ (1,935)
Distributions to WES Operating unitholders	(131,910)					(131,910)						(263,358)					(178,128)				(85,230)
Acquisitions from related parties	(2,007,501)	[1]		(2,141,827)	[1]	106,856	[1]		27,470	[1]		(2,007,501)	[2]		(2,141,827)	[2]	134,326	[2]
Contributions of equity-based compensation from Anadarko/Occidental	1,840					1,840						1,838					1,819				19
Net pre-acquisition contributions from (distributions to) related parties	451,591			451,591								451,591			451,591
Cumulative impact of the Merger transactions	0	[3]				3,169,800	[3]		(3,169,800)	[3]		0	[4]				926,236	[4]	(802,588)	[4]	(123,648)	[4]
Above-market component of swap agreements with Anadarko	7,407	[5]				7,407	[5]					7,407	[6]				7,407	[6]
Amortization of beneficial conversion feature of Class C units												0					(542)		542
Adjustments of net deferred tax liabilities	268,727			273,102		(4,375)						268,727			273,102		(4,375)
Other	(341)					(332)			(9)			268					268
Balance at Mar. 31, 2019	3,591,541			0		3,437,922			153,619			3,591,084			0		3,533,398		0		0		57,686
Balance at Dec. 31, 2018	4,892,683			1,388,018		951,888			2,552,777			4,919,597			1,388,018		2,475,540		791,410		206,862		57,767
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)	387,037											391,429
Balance at Jun. 30, 2019	3,491,210			0		3,338,646			152,564			3,491,046			0		3,433,251		0		0		57,795
Balance at Mar. 31, 2019	3,591,541			0		3,437,922			153,619			3,591,084			0		3,533,398		0		0		57,686
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)	175,058			163		169,431			5,464			176,979			163		174,849						1,967
Distributions to noncontrolling interest owners			(1,858)								(1,858)			(1,858)										(1,858)
Distributions to WES Operating unitholders	(276,324)					(276,324)						(283,271)					(283,271)
Acquisitions from related parties	0	[1]		(5,510)	[1]	4,493	[1]		1,017	[1]		0	[2]		(5,510)	[2]	5,510	[2]
Contributions of equity-based compensation from Anadarko/Occidental	2,768					2,768						2,765					2,765
Net pre-acquisition contributions from (distributions to) related parties	5,347			5,347								5,347			5,347
Other	345					356			(11)
Balance at Jun. 30, 2019	3,491,210			$ 0		3,338,646			152,564			3,491,046			$ 0		3,433,251		$ 0		$ 0		57,795
Balance at Dec. 31, 2019	3,345,293					3,209,947		$ (14,224)	149,570			3,341,819					3,286,620						55,199
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)	(289,400)					(251,396)		(5,131)	(32,873)			(287,995)					(260,330)						(27,665)
Distributions to noncontrolling interest owners			(1,738)								(1,738)			(1,738)										(1,738)
Distributions to WES Operating unitholders	(281,786)					(276,151)		(5,635)				(290,314)					(290,314)
Acquisitions from related parties	0					(3,987)			3,987			0					(3,987)						3,987
Contributions of equity-based compensation from Anadarko/Occidental	4,105					4,105						4,105					4,105
Net contributions from (distributions to) related parties	20,489	[7]				489	[7]		20,000	[7]		20,489	[8]				20,489	[8]
Balance at Mar. 31, 2020	2,792,285					2,684,136		(24,990)	133,139			2,786,366					2,756,583						29,783
Balance at Dec. 31, 2019	3,345,293					3,209,947		(14,224)	149,570			3,341,819					3,286,620						55,199
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)	(8,059)											(5,475)
Balance at Jun. 30, 2020	2,935,517					2,820,327		(22,347)	137,537			2,929,350					2,897,898						31,452
Balance at Mar. 31, 2020	2,792,285					2,684,136		(24,990)	133,139			2,786,366					2,756,583						29,783
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)	281,341					267,576		5,461	8,304			282,520					279,814						2,706
Distributions to noncontrolling interest owners			$ (1,037)								$ (1,037)			$ (1,037)										$ (1,037)
Distributions to WES Operating unitholders	(140,893)					(138,075)		(2,818)				(143,404)					(143,404)
Contributions of equity-based compensation from Anadarko/Occidental	3,562					3,562						3,562					3,562
Net contributions from (distributions to) related parties	1,343					1,343						1,343					1,343
Other	(330)					(330)
Balance at Jun. 30, 2020	$ 2,935,517					$ 2,820,327		$ (22,347)	$ 137,537			$ 2,929,350					$ 2,897,898						$ 31,452
[1]	The amounts allocated to common unitholders and noncontrolling interests represent a non-cash investing activity related to the assets and liabilities assumed in the AMA acquisition. See Note 3 .
[2]	The amount allocated to common unitholders represents a non-cash investing activity related to the assets and liabilities assumed in the AMA acquisition. See Note 3 .
[3]	See Note 1 .
[4]	See Note 1 .
[5]	See Note 6 .
[6]	See Note 6 .
[7]	See December 2019 Agreements—Services, Secondment, and Employee Transfer Agreement within Note 1.
[8]	See December 2019 Agreements—Services, Secondment, and Employee Transfer Agreement within Note 1 .

Consolidated Statements of Ca_3

Consolidated Statements of Cash Flows - WES Operating - USD ($) $ in Thousands		3 Months Ended				6 Months Ended		12 Months Ended
		Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Cash flows from operating activities
Net income (loss)		$ 281,341	$ (289,400)	$ 175,058	$ 211,979	$ (8,059)	$ 387,037
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization		119,805		121,117		252,124	235,063
Long-lived asset impairments		10,150		797		165,935	1,187	$ 6,300
Goodwill impairment		0		0		441,017	0
Non-cash equity-based compensation expense						10,911	5,493
Deferred income taxes						799	4,885
Accretion and amortization of long-term obligations, net						4,297	2,848
Equity income, net – related parties		(54,415)		(63,598)		(115,762)	(121,590)
Distributions from equity-investment earnings – related parties						124,156	115,483
(Gain) loss on divestiture and other, net		2,843		1,061		2,883	1,651
(Gain) loss on early extinguishment of debt		(1,395)		0		(8,740)	0
(Gain) loss on interest-rate swaps						0	94,585
Cash paid to settle interest-rate swaps						(12,763)	0
Other						710	169
Changes in assets and liabilities:
(Increase) decrease in accounts receivable, net						(200,136)	2,668
Increase (decrease) in accounts and imbalance payables and accrued liabilities, net						72,323	(81,198)
Change in other items, net						9,304	38,250
Net cash provided by operating activities						738,999	686,531
Cash flows from investing activities
Capital expenditures						(313,065)	(704,425)
Contributions to equity investments - related parties						(16,064)	(77,333)
Distributions from equity investments in excess of cumulative earnings – related parties						13,340	17,052
Proceeds from the sale of assets to third parties						0	342
Other						(39,212)	0
Net cash used in investing activities						(355,001)	(2,865,168)
Cash flows from financing activities
Borrowings, net of debt issuance costs	[1]					3,586,173	2,710,750
Repayments of debt	[2]					(3,583,149)	(467,595)
Increase (decrease) in outstanding checks						(4,686)	(5,662)
Distributions to WES Operating unitholders	[3]					(422,679)	(408,234)
Net contributions from (distributions to) related parties						21,832	456,938
Above-market component of swap agreements with Anadarko	[3]					0	7,407
Finance lease payments	[4]					(10,262)	0
Net cash provided by (used in) financing activities						(424,222)	2,182,290
Net increase (decrease) in cash and cash equivalents						(40,224)	3,653
Cash and cash equivalents at beginning of period			99,962		92,142	99,962	92,142	92,142
Cash and cash equivalents at end of period		59,738		95,795		59,738	95,795	99,962
Supplemental disclosures
Interest paid, net of capitalized interest						163,362	137,686
Taxes paid (reimbursements received)						(384)	96
Accrued capital expenditures						43,191	141,094
Chipeta [Member]
Cash flows from financing activities
Distributions to Chipeta noncontrolling interest owner						(2,775)	(3,793)
Related Parties [Member]
Cash flows from investing activities
Acquisitions						0	(2,007,501)
Cash flows from financing activities
Borrowings, net of debt issuance costs							11,000
Repayments of debt							(439,600)
Distributions to WES Operating unitholders						(225,914)	(255,885)
Finance lease payments						(6,382)	0
Third Parties [Member]
Cash flows from investing activities
Acquisitions						0	(93,303)
WES Operating [Member]
Cash flows from operating activities
Net income (loss)		282,520	(287,995)	176,979	214,450	(5,475)	391,429
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization		119,805		121,117		252,124	235,063
Long-lived asset impairments		10,150		797		165,935	1,187
Goodwill impairment		0		0		441,017	0
Non-cash equity-based compensation expense						7,667	4,882
Deferred income taxes						799	4,885
Accretion and amortization of long-term obligations, net						4,297	2,827
Equity income, net – related parties		(54,415)		(63,598)		(115,762)	(121,590)
Distributions from equity-investment earnings – related parties						124,156	115,483
(Gain) loss on divestiture and other, net		2,843		1,061		2,883	1,651
(Gain) loss on early extinguishment of debt		(1,395)		0		(8,740)	0
(Gain) loss on interest-rate swaps						0	94,585
Cash paid to settle interest-rate swaps						(12,763)	0
Other						710	169
Changes in assets and liabilities:
(Increase) decrease in accounts receivable, net						(173,522)	2,464
Increase (decrease) in accounts and imbalance payables and accrued liabilities, net						48,923	(80,458)
Change in other items, net						8,664	38,069
Net cash provided by operating activities						740,913	690,646
Cash flows from investing activities
Capital expenditures						(313,065)	(704,425)
Contributions to equity investments - related parties						(16,064)	(77,333)
Distributions from equity investments in excess of cumulative earnings – related parties						13,340	17,052
Proceeds from the sale of assets to third parties						0	342
Other						(39,212)	0
Net cash used in investing activities						(355,001)	(2,865,168)
Cash flows from financing activities
Borrowings, net of debt issuance costs	[5]					3,586,173	2,710,750
Repayments of debt	[6]					(3,583,149)	(439,595)
Increase (decrease) in outstanding checks						(4,690)	(5,662)
Distributions to WES Operating unitholders	[7]					(433,718)	(546,629)
Net contributions from (distributions to) related parties						21,832	456,938
Above-market component of swap agreements with Anadarko	[7]					0	7,407
Finance lease payments	[8]					(10,262)	0
Net cash provided by (used in) financing activities						(426,589)	2,179,416
Net increase (decrease) in cash and cash equivalents						(40,677)	4,894
Cash and cash equivalents at beginning of period			$ 98,122		$ 90,448	98,122	90,448	90,448
Cash and cash equivalents at end of period		$ 57,445		$ 95,342		57,445	95,342	$ 98,122
Supplemental disclosures
Interest paid, net of capitalized interest						163,362	137,452
Taxes paid (reimbursements received)						(384)	96
Accrued capital expenditures						43,191	141,094
WES Operating [Member] | Chipeta [Member]
Cash flows from financing activities
Distributions to Chipeta noncontrolling interest owner						(2,775)	(3,793)
WES Operating [Member] | Related Parties [Member]
Cash flows from investing activities
Acquisitions						0	(2,007,501)
Cash flows from financing activities
Borrowings, net of debt issuance costs							11,000
Repayments of debt							(439,600)
Distributions to WES Operating unitholders						(433,718)	(448,173)
Finance lease payments						(6,400)
WES Operating [Member] | Third Parties [Member]
Cash flows from investing activities
Acquisitions						$ 0	$ (93,303)
[1]	For the six months ended June 30, 2019, includes an $11.0 million borrowing under the APCWH Note Payable.
[2]	For the six months ended June 30, 2019, includes a $439.6 million repayment to settle the APCWH Note Payable. See Note 6 .
[3]	See Note 6 .
[4]	For the six months ended June 30, 2020, includes related-party payments of $6.4 million.
[5]	For the six months ended June 30, 2019, includes an $11.0 million borrowing under the APCWH Note Payable.
[6]	For the six months ended June 30, 2019, includes a $439.6 million repayment to settle the APCWH Note Payable. See Note 6 .
[7]	See Note 6.
[8]	For the six months ended June 30, 2020, includes related-party payments of $6.4 million.

Consolidated Statements of Ca_4

Consolidated Statements of Cash Flows - WES Operating (Parenthetical) - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019
Borrowings, net of debt issuance costs	[1]	$ 3,586,173	$ 2,710,750
Repayments of debt	[2]	3,583,149	467,595
Finance lease payments	[3]	10,262	0
WES Operating [Member]
Borrowings, net of debt issuance costs	[4]	3,586,173	2,710,750
Repayments of debt	[5]	3,583,149	439,595
Finance lease payments	[6]	10,262	0
Related Parties [Member]
Borrowings, net of debt issuance costs			11,000
Repayments of debt			439,600
Finance lease payments		6,382	0
Related Parties [Member] | WES Operating [Member]
Borrowings, net of debt issuance costs			11,000
Repayments of debt			$ 439,600
Finance lease payments		$ 6,400
[1]	For the six months ended June 30, 2019, includes an $11.0 million borrowing under the APCWH Note Payable.
[2]	For the six months ended June 30, 2019, includes a $439.6 million repayment to settle the APCWH Note Payable. See Note 6 .
[3]	For the six months ended June 30, 2020, includes related-party payments of $6.4 million.
[4]	For the six months ended June 30, 2019, includes an $11.0 million borrowing under the APCWH Note Payable.
[5]	For the six months ended June 30, 2019, includes a $439.6 million repayment to settle the APCWH Note Payable. See Note 6 .
[6]	For the six months ended June 30, 2020, includes related-party payments of $6.4 million.

Description of Business and Bas

Description of Business and Basis of Presentation	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Description of Business and Basis of Presentation	1. DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION General. Western Midstream Partners, LP is a Delaware master limited partnership formed in September 2012. Western Midstream Operating, LP (together with its subsidiaries, “WES Operating”) is a Delaware limited partnership formed by Anadarko Petroleum Corporation in 2007 to acquire, own, develop, and operate midstream assets. Western Midstream Partners, LP owns, directly and indirectly, a 98.0% limited partner interest in WES Operating, and directly owns all of the outstanding equity interests of Western Midstream Operating GP, LLC, which holds the entire non-economic general partner interest in WES Operating. “Anadarko” refers to Anadarko Petroleum Corporation and its subsidiaries, excluding Western Midstream Holdings, LLC. Anadarko became a wholly owned subsidiary of Occidental Petroleum Corporation as a result of Occidental Petroleum Corporation’s acquisition by merger of Anadarko on August 8, 2019. For purposes of these consolidated financial statements, the “Partnership” refers to Western Midstream Partners, LP in its individual capacity or to Western Midstream Partners, LP and its subsidiaries, including Western Midstream Operating GP, LLC and WES Operating, as the context requires. “WES Operating GP” refers to Western Midstream Operating GP, LLC, individually as the general partner of WES Operating. The Partnership’s general partner, Western Midstream Holdings, LLC (the “general partner”), is a wholly owned subsidiary of Occidental Petroleum Corporation. “Occidental” refers to Occidental Petroleum Corporation, as the context requires, and its subsidiaries, excluding the general partner. “Related parties” refers to Occidental and the Partnership’s equity interests in Fort Union Gas Gathering, LLC (“Fort Union”), White Cliffs Pipeline, LLC (“White Cliffs”), Rendezvous Gas Services, LLC (“Rendezvous”), Enterprise EF78 LLC (“Mont Belvieu JV”), Texas Express Pipeline LLC (“TEP”), Texas Express Gathering LLC (“TEG”), Front Range Pipeline LLC (“FRP”), Whitethorn Pipeline Company LLC (“Whitethorn LLC”), Cactus II Pipeline LLC (“Cactus II”), Saddlehorn Pipeline Company, LLC (“Saddlehorn”), Panola Pipeline Company, LLC (“Panola”), Mi Vida JV LLC (“Mi Vida”), Ranch Westex JV LLC (“Ranch Westex”), and Red Bluff Express Pipeline, LLC (“Red Bluff Express”). The interests in TEP, TEG, and FRP are referred to collectively as the “TEFR Interests.” “MGR assets” refers to the Red Desert complex and the Granger straddle plant. The “West Texas complex” refers to the Delaware Basin Midstream, LLC (“DBM”) complex and DBJV and Haley systems. The Partnership is engaged in the business of gathering, compressing, treating, processing, and transporting natural gas; gathering, stabilizing, and transporting condensate, natural-gas liquids (“NGLs”), and crude oil; and gathering and disposing of produced water. In its capacity as a natural-gas processor, the Partnership also buys and sells natural gas, NGLs, and condensate on behalf of itself and as an agent for its customers under certain contracts. As of June 30, 2020, the Partnership’s assets and investments consisted of the following: Wholly Operated Non-Operated Equity Gathering systems (1) 17 2 3 2 Treating facilities 38 3 — 3 Natural-gas processing plants/trains 26 3 — 5 NGLs pipelines 2 — — 4 Natural-gas pipelines 5 — — 1 Crude-oil pipelines 3 1 — 3 (1) Includes the DBM water systems. These assets and investments are located in the Rocky Mountains (Colorado, Utah, and Wyoming), North-central Pennsylvania, Texas, and New Mexico. Latham Train II, a cryogenic train at the DJ Basin complex, and Loving ROTF Train III, an oil-stabilization train at the DBM oil system, commenced operations during the first quarter of 2020. 1. DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (CONTINUED) December 2019 Agreements. On December 31, 2019, (i) the Partnership and certain of its subsidiaries, including WES Operating and WES Operating GP, entered into the below-described agreements with Occidental and/or certain of its subsidiaries, including Anadarko, and (ii) WES Operating entered into the below-described amendments to its debt agreements (collectively, the “ December 2019 Agreements ”). • Exchange Agreement. Western Gas Resources, Inc. (“WGRI”), the general partner, and the Partnership entered into a partnership interests exchange agreement (the “Exchange Agreement”), pursuant to which the Partnership canceled the non-economic general partner interest in the Partnership and simultaneously issued a 2.0% general partner interest to the general partner in exchange for which WGRI transferred 9,060,641 common units to the Partnership, which immediately canceled such units on receipt. • Services, Secondment, and Employee Transfer Agreement. Occidental, Anadarko, and WES Operating GP entered into an amended and restated Services, Secondment, and Employee Transfer Agreement (the “Services Agreement”), pursuant to which Occidental, Anadarko, and their subsidiaries (i) seconded certain personnel employed by Occidental to WES Operating GP, in exchange for which WES Operating GP pays a monthly secondment and shared services fee to Occidental equivalent to the direct cost of the seconded employees until their transfer to the Partnership and (ii) agreed to continue to provide certain administrative and operational services to the Partnership for up to a two-year transition period. In January 2020, pursuant to the Services Agreement, Occidental made a one-time cash contribution of $20.0 million to WES Operating for anticipated transition costs required to establish stand-alone human resources and information technology functions. The Services Agreement also includes provisions governing the transfer of certain employees to the Partnership and the assumption by the Partnership of liabilities relating to those employees at the time of their transfer. In late March 2020, seconded employees’ employment was transferred to the Partnership. • RCF amendment. WES Operating entered into an amendment to its $2.0 billion senior unsecured revolving credit facility (“RCF”) to, among other things, (i) effective on February 14, 2020, exercise the final one-year extension option to extend the maturity date of the RCF to February 14, 2025, for the extending lenders, and (ii) modify the change of control definition to provide, among other things, that, subject to certain conditions, if the limited partners of the Partnership elect to remove the general partner as the general partner of the Partnership in accordance with the terms of the partnership agreement, then such removal will not constitute a change of control under the RCF. • Term loan facility amendment. WES Operating entered into an amendment to its $3.0 billion senior unsecured credit facility (“Term loan facility”) to, among other things, modify the change of control definition to provide, among other things, that, subject to certain conditions, if the limited partners of the Partnership elect to remove the general partner as the general partner of the Partnership in accordance with the terms of the partnership agreement, then such removal will not constitute a change of control under the Term loan facility. See Note 11 . • Termination of debt-indemnification agreements. WES Operating GP and certain wholly owned subsidiaries of Occidental mutually terminated the debt-indemnification agreements related to certain indebtedness incurred by WES Operating. • Termination of omnibus agreements. The Partnership and WES Operating entered into agreements with Occidental to terminate the WES and WES Operating omnibus agreements. See Note 6 . 1. DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (CONTINUED) Merger transactions . On February 28, 2019, the Partnership, WES Operating, Anadarko, and certain of their affiliates completed the transactions contemplated by the Contribution Agreement and Agreement and Plan of Merger (the “Merger Agreement”), dated November 7, 2018, pursuant to which, among other things, (i) Clarity Merger Sub, LLC, a wholly owned subsidiary of the Partnership, merged with and into WES Operating, with WES Operating continuing as the surviving entity and as a subsidiary of the Partnership (the “Merger”), and (ii) WES Operating acquired the Anadarko Midstream Assets (“AMA”). See Note 3 . 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, including WES Operating and WES Operating GP. All significant intercompany transactions have been eliminated. The following table outlines the ownership interests and the accounting method of consolidation used in the consolidated financial statements for entities not wholly owned: Percentage Interest Full consolidation Chipeta (1) 75.00 % Proportionate consolidation (2) Springfield system 50.10 % Marcellus Interest systems 33.75 % Equity investments (3) Mi Vida 50.00 % Ranch Westex 50.00 % FRP 33.33 % Red Bluff Express 30.00 % Mont Belvieu JV 25.00 % Rendezvous 22.00 % TEP 20.00 % TEG 20.00 % Whitethorn LLC 20.00 % Saddlehorn 20.00 % Cactus II 15.00 % Panola 15.00 % Fort Union 14.81 % White Cliffs 10.00 % (1) The 25% third-party interest in Chipeta Processing LLC (“Chipeta”) is reflected within noncontrolling interests in the consolidated financial statements. See Noncontrolling interests below. (2) The Partnership proportionately consolidates its associated share of the assets, liabilities, revenues, and expenses attributable to these assets. (3) Investments in non-controlled entities over which the Partnership exercises significant influence are accounted for under the equity method of accounting. “Equity-investment throughput” refers to the Partnership’s share of average throughput for these investments. 1. DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (CONTINUED) The consolidated financial results of WES Operating are included in the Partnership’s consolidated financial statements. Throughout these notes to consolidated financial statements, and to the extent material, any differences between the consolidated financial results of the Partnership and WES Operating are discussed separately. The Partnership’s consolidated financial statements differ from those of WES Operating primarily as a result of (i) the presentation of noncontrolling interest ownership (see Noncontrolling interests below and Note 5 ), (ii) the elimination of WES Operating GP’s investment in WES Operating with WES Operating GP’s underlying capital account, (iii) the general and administrative expenses incurred by the Partnership, which are separate from, and in addition to, those incurred by WES Operating, (iv) the inclusion of the impact of Partnership equity balances and Partnership distributions, and (v) the senior secured revolving credit facility (“WGP RCF”) until its repayment in March 2019. See Note 11 . Presentation of the Partnership’s assets. The Partnership’s assets include assets owned and ownership interests accounted for by the Partnership under the equity method of accounting, through its 98.0% partnership interest in WES Operating as of June 30, 2020 (see Note 7 ). The Partnership also owns and controls the entire non-economic general partner interest in WES Operating GP, and the Partnership’s general partner is owned by Occidental. Use of estimates. 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 reasonable methods. 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 included 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. Noncontrolling interests. For periods subsequent to Merger completion, the Partnership’s noncontrolling interests in the consolidated financial statements consist of (i) the 25% third-party interest in Chipeta and (ii) the 2.0% Occidental subsidiary-owned limited partner interest in WES Operating. For periods prior to Merger completion, the Partnership’s noncontrolling interests in the consolidated financial statements consisted of (i) the 25% third-party interest in Chipeta, (ii) the publicly held limited partner interests in WES Operating, (iii) the common units issued by WES Operating to subsidiaries of Anadarko as part of the consideration paid for prior-period acquisitions from Anadarko, and (iv) the Class C units issued by WES Operating to a subsidiary of Anadarko as part of the funding for the acquisition of DBM. For all periods presented, WES Operating’s noncontrolling interest in the consolidated financial statements consists of the 25% third-party interest in Chipeta. See Note 5. When WES Operating issues equity, the carrying amount of the noncontrolling interest reported by the Partnership is adjusted to reflect the noncontrolling ownership interest in WES Operating. The resulting impact of such noncontrolling interest adjustment on the Partnership’s interest in WES Operating is reflected as an adjustment to the Partnership’s partners’ capital. Inventory. The cost of NGLs inventory is determined by the weighted-average cost method on a location-by-location basis. Inventory is stated at the lower of weighted-average cost or net realizable value. NGLs inventory is reported in Other current assets and NGLs line-fill inventory is reported in Other assets on the consolidated balance sheets. Materials and supplies inventory is valued at weighted-average cost and is reviewed periodically for obsolescence. As of June 30, 2020, materials and supplies inventory, previously reported in Other current assets, is prospectively reported in Other assets on the consolidated balance sheets. See Note 10 . 1. DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (CONTINUED) Shutdown of gathering systems. In May 2018, after assessing a number of factors, and with the safety of the community and the protection of the environment as primary factors, the Partnership permanently ceased operations at the Kitty Draw gathering system in Wyoming (part of the Hilight system) and the Third Creek gathering system in Colorado (part of the DJ Basin complex). An accrual of $10.9 million for anticipated costs associated with system shutdowns was recorded in 2018 as a reduction in related-party Product sales in the consolidated statements of operations. During the first quarter of 2019, $5.5 million of the accrual related to the Kitty Draw gathering system was reversed due to producer settlements being less than their initial estimates. Segments. The Partnership’s operations continue to be organized into a single operating segment, the assets of which gather, compress, treat, process, and transport natural gas; gather, stabilize, and transport condensate, NGLs, and crude oil; and gather and dispose of produced water in the United States. Equity-based compensation. On February 10, 2020, the Board of Directors approved awards of phantom units (the “Awards”) to the Partnership’s executive officers under the Western Gas Equity Partners, LP 2012 Long-Term Incentive Plan (“WES LTIP”). The Awards include (i) an award of time-vested phantom units that vest ratably over a three-year period (“Time-Based Awards”), (ii) a market award that vests after a three-year performance period based on the Partnership’s relative total unitholder return as compared to a group of peer companies (“TUR Awards”), and (iii) a performance award that vests based on the Partnership’s average return on assets over a three-year performance period (“ROA Awards”). At vesting, the value of the TUR Awards and the ROA Awards will be determined in accordance with the terms of the respective Award Agreements that provide for payout percentages ranging from 0% to 200% based on results achieved over the applicable performance period. At vesting, the Awards generally will be settled in Partnership common units. Prior to vesting, the Awards pay in-kind distributions in the form of Partnership common units. The Partnership issued 21,090 common units as in-kind distributions under such Awards during the quarter ended June 30, 2020. In addition, phantom units are awarded under the WES LTIP to non-executive employees and independent directors of the Partnership from time to time, which vest ratably over a three-year period and one year from the grant date, respectively. Prior to vesting, the awards to non-executive employees and independent directors pay distribution equivalents in cash. The equity-based compensation expense attributable to these awards is amortized over the vesting periods applicable to the awards using the straight-line method. Expense is recognized based on the grant-date fair value and recorded, net of any forfeitures, as General and administrative expense in the consolidated statements of operations. The fair value of the Time-based Awards, ROA Awards, and non-executive awards is based on the observable market price of the Partnership’s units on the grant date of the award. The fair value of the TUR Awards is determined using a Monte Carlo simulation at the grant date of the award. For ROA Awards, all performance-related fair-value changes are recognized in compensation expense during the performance period. Compensation expense for the WES LTIP was $2.1 million and $3.2 million for the three and six months ended June 30, 2020, respectively, and $0.4 million for the three and six months ended June 30, 2019. Defined-contribution plan. Beginning in the first quarter of 2020, employees of the Partnership are eligible to participate in the Western Midstream Savings Plan, a defined-contribution benefit plan maintained by the Partnership. All regular employees may participate in the plan by making elective contributions that are matched by the Partnership, subject to certain limitations. The Partnership also makes other contributions based on plan guidelines. The Partnership recognized expense related to the plan of $4.0 million and $4.4 million for the three and six months ended June 30, 2020, respectively, recorded as General and administrative expense in the consolidated statements of operations. 1. DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (CONTINUED) Recently adopted accounting standards. Accounting Standards Update (“ASU”) 2016-13, Financial Instruments - Credit Losses (Topic 326) significantly changes the accounting and disclosure requirements related to credit losses on financial assets. Under the new standard, entities are now required to estimate lifetime expected credit losses for trade receivables, loans, and other financial instruments as of the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts, resulting in earlier recognition of credit losses. There was no impact to the consolidated financial statements with the Partnership’s adoption of the standard on January 1, 2020. The Partnership has implemented the necessary changes to its processes and controls to support accounting and disclosure requirements under this ASU. Accounts receivable and contract assets. Accounts receivable represent contractual rights for services performed, with, on average, 30-day payment terms from the date of invoice. Contract assets primarily relate to revenue accrued but not yet billed under cost-of-service contracts and accrued deficiency fees. As of June 30, 2020, there have been no negative indications regarding the collectability of significant receivables as it relates to impacts from the global outbreak of the coronavirus (“COVID-19”) and the oil-market disruption resulting from significantly lower global demand and corresponding oversupply of crude oil. The Partnership will continue to monitor the credit quality of its customer base and assess collectability of these assets as appropriate. Notes receivable. In May 2008, WES Operating 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 “Anadarko note receivable”). Following Occidental’s acquisition by merger of Anadarko in August 2019, Occidental became the ultimate counterparty. Since the first quarter of 2020, the Partnership has assessed the recoverability of the Anadarko note receivable under the loss-given-default method using historical data from internal and external sources, current market conditions, and reasonable and supportable forecasted information. The loss-given-default method was based on applicable probability of default percentages for similar debt instruments and the fair value of the Anadarko note receivable, which reflects an analysis of Occidental’s yield based on quoted market yields of similar Occidental debt instruments. As of June 30, 2020, the Partnership recognized an allowance for expected credit losses of $0.5 million related to the Anadarko note receivable. See Note 6 .

Revenue from Contracts with Cus

Revenue from Contracts with Customers	6 Months Ended
	Jun. 30, 2020
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	2. REVENUE FROM CONTRACTS WITH CUSTOMERS The following table summarizes revenue from contracts with customers: Three Months Ended Six Months Ended thousands 2020 2019 2020 2019 Revenue from customers Service revenues – fee based $ 581,452 $ 593,544 $ 1,223,373 $ 1,173,518 Service revenues – product based 7,000 16,675 22,921 36,054 Product sales 21,736 74,469 78,385 147,269 Total revenue from customers 610,188 684,688 1,324,679 1,356,841 Revenue from other than customers Lease revenue (1) 61,176 — 120,651 — Net gains (losses) on commodity-price swap agreements — — — (667) Other 391 366 738 763 Total revenues and other $ 671,755 $ 685,054 $ 1,446,068 $ 1,356,937 (1) For the three and six months ended June 30, 2020, includes fixed- and variable-lease revenue from an operating and maintenance agreement entered into with Occidental. See Operating lease within Note 6. 2. REVENUE FROM CONTRACTS WITH CUSTOMERS (CONTINUED) Contract balances. Receivables from customers, which are included in Accounts receivable, net on the consolidated balance sheets were $507.3 million and $362.6 million as of June 30, 2020, and December 31, 2019, respectively. Contract assets primarily relate to revenue accrued but not yet billed under cost-of-service contracts with fixed and variable fees and accrued deficiency fees the Partnership expects to charge customers once the related performance periods are completed. The following table summarizes current-period activity related to contract assets from contracts with customers: thousands Balance at December 31, 2019 $ 67,357 Amounts transferred to Accounts receivable, net that were included in the contract assets balance at the beginning of the period (1) (2,592) Additional estimated revenues recognized (2) 9,646 Balance at June 30, 2020 $ 74,411 Contract assets at June 30, 2020 Other current assets $ 15,084 Other assets 59,327 Total contract assets from contracts with customers $ 74,411 (1) Includes $(2.6) million for the three months ended June 30, 2020. (2) Includes $4.3 million for the three months ended June 30, 2020. Contract liabilities primarily relate to (i) fees that are charged to customers for only a portion of the contract term and must be recognized as revenues over the expected period of customer benefit, (ii) fixed and variable fees under cost-of-service contracts that are received from customers for which revenue recognition is deferred, and (iii) aid-in-construction payments received from customers that must be recognized over the expected period of customer benefit. The following table summarizes current-period activity related to contract liabilities from contracts with customers: thousands Balance at December 31, 2019 $ 222,274 Cash received or receivable, excluding revenues recognized during the period (1) 23,902 Revenues recognized that were included in the contract liability balance at the beginning of the period (2) (10,533) Balance at June 30, 2020 $ 235,643 Contract liabilities at June 30, 2020 Accrued liabilities $ 9,231 Other liabilities 226,412 Total contract liabilities from contracts with customers $ 235,643 (1) Includes $12.7 million for the three months ended June 30, 2020. (2) Includes $(1.6) million for the three months ended June 30, 2020. 2. REVENUE FROM CONTRACTS WITH CUSTOMERS (CONTINUED) Transaction price allocated to remaining performance obligations. Revenues expected to be recognized from certain performance obligations that are unsatisfied (or partially unsatisfied) as of June 30, 2020, are presented in the following table. The Partnership applies the optional exemptions in Topic 606 and does not disclose consideration for remaining performance obligations with an original expected duration of one year or less or for variable consideration related to unsatisfied (or partially unsatisfied) performance obligations. Therefore, the following table represents only a portion of expected future revenues from existing contracts as most future revenues from customers are dependent on future variable customer volumes and, in some cases, variable commodity prices for those volumes. thousands Remainder of 2020 $ 387,163 2021 779,043 2022 1,033,556 2023 977,039 2024 946,468 Thereafter 3,551,258 Total $ 7,674,527

Acquisitions and Divestitures

Acquisitions and Divestitures	6 Months Ended
	Jun. 30, 2020
Property, Plant and Equipment [Abstract]
Acquisitions and Divestitures	3. ACQUISITIONS AND DIVESTITURES AMA acquisition. In February 2019, WES Operating acquired AMA from Anadarko, which is comprised of (i) the DJ Basin oil system and Wattenberg processing plant located in the DJ basin; (ii) the DBM oil system, APC water systems, a 50% interest in Mi Vida, and a 50% interest in Ranch Westex, located in West Texas; (iii) the Wamsutter pipeline located in Wyoming; (iv) a 20% interest in Saddlehorn, a crude-oil and condensate pipeline that originates in Laramie County, Wyoming and terminates in Cushing, Oklahoma; and (v) a 15% interest in Panola, an NGLs pipeline that originates in Panola County, Texas, and terminates in Mont Belvieu, Texas. AMA was acquired in exchange for aggregate consideration of $2.0 billion of cash, less the outstanding amount payable pursuant to an intercompany note (the “APCWH Note Payable”) assumed by WES Operating in connection with the transfer, and 45,760,201 WES Operating common units. These WES Operating common units, less 6,375,284 WES Operating common units retained by WGR Asset Holding Company LLC (“WGRAH”), converted into the right to receive common units of the Partnership at Merger completion. Red Bluff Express acquisition. In January 2019, the Partnership acquired a 30% interest in Red Bluff Express, which owns a third-party-operated natural-gas pipeline connecting processing plants in Reeves and Loving Counties, Texas, to the WAHA hub in Pecos County, Texas. The Partnership acquired its 30% interest from a third party via an initial net investment of $92.5 million, which represented a 30% share of costs incurred up to the date of acquisition. The initial investment was funded with cash on hand and the interest in Red Bluff Express is accounted for under the equity method of accounting.

Partnership Distributions

Partnership Distributions	6 Months Ended
	Jun. 30, 2020
Distributions Made to Members or Limited Partners [Abstract]
Partnership Distributions	4. PARTNERSHIP DISTRIBUTIONS Partnership distributions. The partnership agreement requires the Partnership to distribute all of its available cash (as defined in its partnership agreement) to unitholders of record on the applicable record date within 55 days following each quarter’s end. The Board of Directors of the general partner (the “Board of Directors”) declared the following cash distributions to the Partnership’s unitholders for the periods presented: thousands except per-unit amounts Quarters Ended Total Quarterly Total Quarterly Distribution 2019 March 31 $ 0.61000 $ 276,324 May 2019 June 30 0.61800 279,959 August 2019 September 30 0.62000 280,880 November 2019 December 31 0.62200 281,786 February 2020 2020 March 31 $ 0.31100 $ 140,893 May 2020 June 30 (1) 0.31100 140,900 August 2020 (1) The Board of Directors declared a cash distribution to the Partnership’s unitholders for the second quarter of 2020 of $0.31100 per unit, or $140.9 million in aggregate. The cash distribution is payable on August 13, 2020 to unitholders of record at the close of business on July 31, 2020, including the general partner units that were issued on December 31, 2019 (see Note 1 ). Following the transactions contemplated by the Exchange Agreement, the general partner is entitled to 2.0% of all quarterly distributions beginning with the cash distribution declared for the fourth quarter of 2019. Available cash. The amount of available cash (as defined in the partnership agreement) generally is all cash on hand at the end of the quarter, plus, at the discretion of the general partner, working capital borrowings made subsequent to the end of such quarter, less the amount of cash reserves established by the general partner to provide for the proper conduct of the Partnership’s business, including reserves to fund future capital expenditures; to comply with applicable laws, debt instruments, or other agreements; or to provide funds for unitholder distributions for any one or more of the next four quarters. Working capital borrowings generally include borrowings made under a credit facility or similar financing arrangement. Working capital borrowings generally are intended to be repaid or refinanced within 12 months. In all cases, working capital borrowings are used solely for working capital purposes or to fund unitholder distributions. WES Operating partnership distributions. Immediately prior to the closing of the Merger, the WES Operating incentive distribution rights (“IDRs”) and general partner units were converted into WES Operating common units and a non-economic general partner interest in WES Operating, and at Merger completion, all WES Operating common units held by the public and subsidiaries of Anadarko (other than common units held by the Partnership, WES Operating GP, and 6.4 million common units held by a subsidiary of Anadarko) were converted into common units of the Partnership. Beginning with the first quarter of 2019, WES Operating has made cash distributions to the Partnership and WGRAH, a subsidiary of Occidental, in respect of their proportionate share of limited partner interests in WES Operating. See Note 5 . 4. PARTNERSHIP DISTRIBUTIONS (CONTINUED) WES Operating made the following cash distributions to its limited partners for the periods presented: thousands Quarters Ended Total Quarterly 2019 March 31 $ 283,271 June 30 288,083 September 30 289,676 December 31 290,314 2020 March 31 $ 143,404 June 30 143,404

Equity and Partners' Capital

Equity and Partners' Capital	6 Months Ended
	Jun. 30, 2020
Partners' Capital Notes [Abstract]
Equity and Partners' Capital	5. EQUITY AND PARTNERS’ CAPITAL Holdings of Partnership equity. The Partnership’s common units are listed on the New York Stock Exchange under the ticker symbol “WES.” As of June 30, 2020, Occidental held 242,136,976 common units, representing a 53.4% limited partner interest in the Partnership, and through its ownership of the general partner, Occidental indirectly held 9,060,641 general partner units, representing a 2.0% general partner interest in the Partnership (see Note 1 ). The public held 201,855,523 common units, representing a 44.6% limited partner interest in the Partnership. Holdings of WES Operating equity. As of June 30, 2020, (i) the Partnership, directly and indirectly through its ownership of WES Operating GP, owned a 98.0% limited partner interest and the entire non-economic general partner interest in WES Operating and (ii) Occidental, through its ownership of WGRAH, owned a 2.0% limited partner interest in WES Operating, which is reflected as a noncontrolling interest within the consolidated financial statements of the Partnership (see Note 1 ). WES Operating Class C units. In November 2014, WES Operating issued 10,913,853 Class C units to APC Midstream Holdings, LLC (“AMH”), pursuant to a Unit Purchase Agreement with Anadarko and AMH. The Class C units were issued to partially fund the acquisition of DBM. All outstanding Class C units converted into WES Operating common units on a one-for-one basis immediately prior to the closing of the Merger (see Note 1 ). Partnership’s net income (loss) per common unit. Following the transactions contemplated by the Exchange Agreement, the common and general partner unitholders’ allocation of net income (loss) attributable to the Partnership was equal to their cash distributions plus their respective allocations of undistributed earnings or losses using the two-class method. Specifically, net income equal to the amount of available cash (as defined by the partnership agreement) was allocated to the common and general partner unitholders consistent with actual cash distributions and capital account allocations. Undistributed earnings (net income in excess of distributions) or undistributed losses (available cash in excess of net income (loss)) were then allocated to the common and general partner unitholders in accordance with their weighted-average ownership percentage during each period. The Partnership’s basic net income (loss) per common unit is calculated by dividing the limited partners’ interest in net income (loss) by the weighted-average number of common units outstanding during the period. Net income (loss) attributable to assets acquired from Anadarko for periods prior to the acquisition of such assets was not allocated to the limited partners when calculating net income (loss) per common unit. WES Operating’s net income (loss) per common unit. For periods subsequent to the closing of the Merger, net income (loss) per common unit for WES Operating is not calculated because no publicly traded units remained outstanding subsequent to the closing of the Merger.

Related-Party Transactions

Related-Party Transactions	6 Months Ended
	Jun. 30, 2020
Related Party Fees and Other Arrangements, Limited Liability Company (LLC) or Limited Partnership (LP) [Abstract]
Related-Party Transactions	6. RELATED-PARTY TRANSACTIONS Summary of related-party transactions. The following tables summarize material related-party transactions included in the Partnership’s consolidated financial statements: Consolidated statements of operations Three Months Ended Six Months Ended thousands 2020 2019 2020 2019 Revenues and other Service revenues – fee based $ 460,138 $ 343,484 $ 907,921 $ 670,126 Service revenues – product based 1,168 634 4,146 1,986 Product sales 12,136 41,066 43,760 91,509 Total revenues and other 473,442 385,184 955,827 763,621 Equity income, net – related parties (1) 54,415 63,598 115,762 121,590 Operating expenses Cost of product 5,967 68,225 83,870 124,397 Operation and maintenance 1,516 32,318 34,357 71,459 General and administrative (2) 10,994 26,892 32,849 45,786 Total operating expenses 18,477 127,435 151,076 241,642 Interest income – Anadarko note receivable 4,225 4,225 8,450 8,450 Interest expense — (20) (43) (1,853) (1) See Note 7 . (2) Includes amounts charged by Occidental pursuant to the shared services agreements (see Shared services agreements within this Note 6 ). Also see Incentive Plans within this Note 6. Consolidated balance sheets thousands June 30, December 31, Assets Accounts receivable, net (1) $ 325,349 $ 113,345 Other current assets 13,019 4,982 Anadarko note receivable 259,481 260,000 Equity investments (2) 1,280,047 1,285,717 Other assets 59,302 60,221 Total assets 1,937,198 1,724,265 Liabilities Accounts and imbalance payables 655 — Short-term debt (3) — 7,873 Accrued liabilities 2,513 3,087 Other liabilities 119,132 97,800 Total liabilities 122,300 108,760 (1) Increase attributable to the timing of certain related-party cash receipts. The Partnership received $141.8 million of the June 30, 2020, Accounts receivable, net balance by July 3, 2020. (2) See Note 7 . (3) Includes amounts related to finance leases (see Note 11 ) . 6. RELATED-PARTY TRANSACTIONS (CONTINUED) Consolidated statements of cash flows Six Months Ended thousands 2020 2019 Distributions from equity-investment earnings – related parties $ 124,156 $ 115,483 Acquisitions from related parties — (2,007,501) Contributions to equity investments - related parties (16,064) (77,333) Distributions from equity investments in excess of cumulative earnings – related parties 13,340 17,052 APCWH Note Payable borrowings — 11,000 Repayment of APCWH Note Payable — (439,595) Distributions to Partnership unitholders (1) (225,914) (255,885) Distributions to WES Operating unitholders (2) (8,676) (8,210) Net contributions from (distributions to) related parties 21,832 456,938 Above-market component of swap agreements with Anadarko — 7,407 Finance lease payments (6,382) — (1) Represents distributions paid to Occidental pursuant to the partnership agreement of the Partnership (see Note 4 and Note 5 ). (2) Represents distributions paid to certain subsidiaries of Occidental pursuant to WES Operating’s partnership agreement (see Note 4 and Note 5 ). The following tables summarize material related-party transactions for WES Operating (which are included in the Partnership’s consolidated financial statements) to the extent the amounts differ from the Partnership’s consolidated financial statements: Consolidated statements of operations Three Months Ended Six Months Ended thousands 2020 2019 2020 2019 General and administrative (1) $ 11,168 $ 26,380 $ 32,906 $ 44,878 (1) Includes amounts charged by Occidental pursuant to the shared services agreements (see Shared services agreements within this Note 6 ). Also see Incentive Plans within this Note 6. Consolidated balance sheets thousands June 30, December 31, Accounts receivable, net $ 299,332 $ 113,581 Consolidated statements of cash flows Six Months Ended thousands 2020 2019 Distributions to WES Operating unitholders (1) $ (433,718) $ (448,173) (1) Represents distributions paid to the Partnership and certain subsidiaries of Occidental pursuant to WES Operating’s partnership agreement (see Note 4 and Note 5 ). For the six months ended June 30, 2019, includes distributions to the Partnership and a subsidiary of Occidental related to the repayment of the WGP RCF (see Note 11 ). 6. RELATED-PARTY TRANSACTIONS (CONTINUED) Related-party revenues. Related-party revenues include (i) income from the Partnership’s investments accounted for under the equity method of accounting (see Note 7 ) and (ii) amounts earned by the Partnership from services provided to Occidental and from the sale of natural gas, condensate, and NGLs to Occidental. Gathering and processing agreements. The Partnership has significant gathering and processing arrangements with affiliates of Occidental on most of its systems. These arrangements with Occidental include Occidental-produced volumes and in some instances, the volumes of other working-interest owners of Occidental where the joint partnership collectively markets volumes. These volumes are considered owned and controlled by Occidental, which is the contracting counterparty of the Partnership. Natural-gas throughput (excluding equity-investment throughput) attributable to production owned or controlled by Occidental was 43% and 42% for the three and six months ended June 30, 2020, respectively, and 37% for the three and six months ended June 30, 2019. Crude-oil and NGLs throughput (excluding equity-investment throughput) attributable to production owned or controlled by Occidental was 88% for the three and six months ended June 30, 2020, and 85% and 83% for the three and six months ended June 30, 2019, respectively. Produced-water throughput attributable to production owned or controlled by Occidental was 87% and 88% for the three and six months ended June 30, 2020, respectively, and 80% and 82% for the three and six months ended June 30, 2019, respectively. Commodity purchase and sale agreements. The Partnership sells a significant amount of its natural gas and NGLs to Anadarko Energy Services Company (“AESC”), Occidental’s marketing affiliate. Prior to April 1, 2020, AESC acted as an agent on behalf of either the Partnership or the Partnership’s customers for third-party sales. Where AESC sold natural gas and NGLs on the Partnership’s customers’ behalf, the Partnership recognized associated service revenues and cost of product expense for the marketing services performed by AESC. When product sales were on the Partnership’s behalf, the Partnership recognized product sales revenues based on Occidental’s sales price to the third party and recorded the associated cost of product expense associated with the marketing activities provided by AESC. Effective April 1, 2020, changes to marketing-contract terms with AESC terminated AESC’s prior status as an agent of the Partnership for third-party sales and established AESC as a customer of the Partnership. Accordingly, the Partnership no longer recognizes service revenues and/or product sales revenues and the equivalent cost of product expense for the marketing services performed by AESC. This change has no impact to Operating income (loss), Net income (loss), the balance sheets, cash flows, or any non-GAAP metric used to evaluate the Partnership’s operations (see Key Performance Metrics under Part I, Item 2 of this Form 10-Q). In addition, the Partnership purchases natural gas from AESC pursuant to purchase agreements. Marketing Transition Services Agreement. Effective December 31, 2019, certain subsidiaries of Anadarko entered into a transition services agreement (the “Marketing Transition Services Agreement”) to provide marketing-related services to certain of the Partnership’s subsidiaries through December 31, 2020. Additionally, under the terms of the Marketing Transition Services Agreement, the Partnership is liable for certain downstream transportation commitments through December 31, 2020. Operating lease. Effective December 31, 2019, an affiliate of Occidental and a wholly owned subsidiary of the Partnership entered into an operating and maintenance agreement pursuant to which Occidental provides operational and maintenance services with respect to a crude-oil gathering system and associated treating facilities owned by the Partnership through December 31, 2021. The agreement and underlying contracts include (i) fixed consideration, which is measured as the minimum-volume commitment for both gathering and treating, and (ii) variable consideration, which consists of all volumes above the minimum-volume commitment. Subsequent to the initial two-year term, the agreement provides for automatic one-year extensions, unless either party exercises its option to terminate the lease with advance notice. For the three and six months ended June 30, 2020, the Partnership recognized fixed-lease revenue of $44.0 million and $87.9 million, respectively, and variable-lease revenue of $17.2 million and $32.8 million, respectively, related to these agreements, with such amounts included in Service revenues – fee based in the consolidated statements of operations. 6. RELATED-PARTY TRANSACTIONS (CONTINUED) Related-party expenses. Operation and maintenance expense includes amounts accrued for or paid to related parties for the operation of the Partnership’s assets and for services provided to related parties, including field labor, measurement and analysis, and other disbursements. A portion of general and administrative expense is paid by Occidental, which results in related-party transactions pursuant to the reimbursement provisions of the Partnership’s and WES Operating’s agreements with Occidental. Related-party expenses do not bear a direct relationship to related-party revenues, and third-party expenses do not bear a direct relationship to third-party revenues. Shared services agreements. Pursuant to the agreements discussed below, Occidental performs certain centralized corporate functions for the Partnership and WES Operating. • Services Agreement. Pursuant to the Services Agreement, which was amended and restated on December 31, 2019, specified employees of Occidental were seconded to WES Operating GP to provide, under the direction, supervision, and control of the general partner, (i) operating and routine maintenance service and (ii) corporate, administrative, and other services, with respect to the assets owned and operated by the Partnership. Occidental is reimbursed for the services provided by the seconded employees. In late March 2020, seconded employees’ employment was transferred to the Partnership. Further, Occidental continues to provide certain administrative and operational services to the Partnership. In January 2020, pursuant to the Services Agreement, Occidental made a one-time cash contribution of $20.0 million to WES Operating for anticipated transition costs required to establish stand-alone human resources and information technology functions. For additional information on the Services Agreement, see Note 1 . • WES and WES Operating omnibus agreements. Prior to December 31, 2019, the Partnership had an omnibus agreement with Occidental and the general partner and WES Operating had a separate omnibus agreement with Occidental and WES Operating GP. These agreements governed, among other things, the obligation to reimburse Occidental for expenses incurred or payments made on the Partnership’s and WES Operating’s behalf in conjunction with general and administrative services provided by Occidental. The omnibus agreements were terminated as part of the December 2019 Agreements (see Note 1 ). Incentive Plans. General and administrative expense includes equity-based compensation expense allocated to the Partnership by Occidental for awards granted to the executive officers of the general partner and to other employees prior to their employment with the Partnership under (i) the Anadarko Petroleum Corporation 2012 Omnibus Incentive Compensation Plan, as amended and restated, (ii) Occidental’s 2015 Long-Term Incentive Plan, and (iii) Occidental’s Phantom Share Unit Award Plan (collectively referred to as the “Incentive Plans”). General and administrative expense includes costs related to the Incentive Plans of $3.6 million and $7.7 million for the three and six months ended June 30, 2020, respectively, and $4.0 million and $5.8 million for the three and six months ended June 30, 2019, respectively. Portions of these amounts are reflected as contributions to partners’ capital in the consolidated statements of equity and partners’ capital. December 2019 Agreements. As discussed in more detail in Note 1 , on December 31, 2019, the Partnership and certain of its subsidiaries, including WES Operating and WES Operating GP, entered into agreements with Occidental and/or certain of its subsidiaries, including Anadarko. Merger transactions. As discussed in more detail in Note 1 , on February 28, 2019, the Partnership, WES Operating, Anadarko, and certain of their affiliates completed the Merger and the other transactions contemplated in the Merger Agreement, which included the acquisition of AMA from Anadarko. See Note 3. 6. RELATED-PARTY TRANSACTIONS (CONTINUED) Anadarko note receivable. In May 2008, WES Operating 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 and classified as interest income in the consolidated statements of operations. As of June 30, 2020, the accrued interest receivable balance of $2.8 million is classified as Accounts receivable, net on the consolidated balance sheets. The fair value of the Anadarko note receivable was $241.5 million and $337.7 million at June 30, 2020, and December 31, 2019, respectively. Following Occidental’s acquisition by merger of Anadarko, the fair value of the Anadarko note receivable reflects an analysis of Occidental’s yield based on quoted market yields of similar Occidental debt instruments. Accordingly, the fair value of the Anadarko note receivable is measured using Level-2 fair value inputs. As of June 30, 2020, the Partnership recognized an allowance for expected credit losses of $0.5 million related to the Anadarko note receivable. See Note 1 . APCWH Note Payable. In June 2017, APC Water Holdings 1, LLC (“APCWH”) entered into an eight-year note payable agreement with Anadarko, which was repaid in the first quarter of 2019 at the Merger completion date. See Note 11 . Commodity-price swap agreements. WES Operating previously entered into commodity-price swap agreements with Anadarko to mitigate exposure to the commodity-price risk inherent in WES Operating’s percent-of-proceeds, percent-of-product, and keep-whole natural-gas processing contracts. These commodity-price swap agreements expired without renewal on December 31, 2018. Notional volumes for each product-based commodity-price swap agreement were not specifically defined. Instead, the commodity-price swap agreements applied to the actual volumes of natural gas, condensate, and NGLs purchased and sold. The commodity-price swap agreements did not satisfy the definition of a derivative financial instrument and, therefore did not require fair-value measurement. Net gains (losses) on commodity-price swap agreements were zero and $(0.7) million (due to settlement of 2018 activity in 2019) for the three and six months ended June 30, 2019, respectively, reported in the consolidated statements of operations as related-party Product sales. A capital contribution from Anadarko related to the commodity-price swap agreements of $7.4 million was recorded in the consolidated statements of equity and partners’ capital for the three months ended March 31, 2019. Concentration of credit risk. Occidental was the only customer from which revenues exceeded 10% of consolidated revenues for all periods presented in the consolidated statements of operations.

Equity Investments

Equity Investments	6 Months Ended
	Jun. 30, 2020
Equity Method Investments and Joint Ventures [Abstract]
Equity Investments	7. EQUITY INVESTMENTS The following table presents the equity-investments activity for the six months ended June 30, 2020: thousands Balance at December 31, 2019 Equity Contributions Distributions Distributions in excess of cumulative earnings (1) Balance at June 30, 2020 Fort Union $ (610) $ (566) $ — $ — $ — $ (1,176) White Cliffs 45,877 4,368 993 (3,826) (679) 46,733 Rendezvous 32,964 187 — (1,158) (1,072) 30,921 Mont Belvieu JV 103,036 13,734 — (13,753) (2,897) 100,120 TEG 18,199 2,198 — (2,209) (1,356) 16,832 TEP 203,556 18,410 — (21,588) (592) 199,786 FRP 207,782 19,909 3,670 (21,340) (4,193) 205,828 Whitethorn LLC 161,665 19,957 278 (20,811) — 161,089 Cactus II 172,165 10,955 10,471 (11,092) — 182,499 Saddlehorn 112,855 12,223 — (13,644) — 111,434 Panola 21,783 984 — (984) (431) 21,352 Mi Vida 57,807 5,178 — (5,925) (478) 56,582 Ranch Westex 46,678 5,648 — (5,249) (705) 46,372 Red Bluff Express 101,960 2,577 652 (2,577) (937) 101,675 Total $ 1,285,717 $ 115,762 $ 16,064 $ (124,156) $ (13,340) $ 1,280,047 (1) Distributions in excess of cumulative earnings, classified as investing cash flows in the consolidated statements of cash flows, are calculated on an individual-investment basis. The investment balance in Saddlehorn at June 30, 2020, is $9.8 million less than the Partnership’s underlying equity in Saddlehorn’s net assets, primarily due to income from an expansion project that was funded by Saddlehorn’s other owners being disproportionately allocated to the Partnership beginning in the second quarter of 2020. This difference will be amortized to Equity income, net – related parties in the consolidated statements of operations over the remaining estimated useful life of the Saddlehorn pipeline.

Property, Plant, and Equipment

Property, Plant, and Equipment	6 Months Ended
	Jun. 30, 2020
Property, Plant and Equipment [Abstract]
Property, Plant, and Equipment	8. PROPERTY, PLANT, AND EQUIPMENT A summary of the historical cost of property, plant, and equipment is as follows: thousands Estimated Useful Life June 30, December 31, Land N/A $ 9,708 $ 9,495 Gathering systems – pipelines 30 years 5,203,293 5,092,004 Gathering systems – compressors 15 years 2,033,154 1,929,377 Processing complexes and treating facilities 25 years 3,380,567 3,237,801 Transportation pipeline and equipment 6 to 45 years 171,069 173,572 Produced-water disposal systems 20 years 810,275 754,774 Assets under construction N/A 289,418 486,584 Other 3 to 40 years 702,238 672,064 Total property, plant, and equipment 12,599,722 12,355,671 Less accumulated depreciation 3,685,006 3,290,740 Net property, plant, and equipment $ 8,914,716 $ 9,064,931 The cost of property classified as “Assets under construction” is excluded from capitalized costs being depreciated. These amounts represent property that is not yet placed into productive service as of the respective balance sheet date. Long-lived asset impairments. During the six months ended June 30, 2020, the Partnership recognized impairments of $165.9 million, primarily due to $149.4 million of impairments for assets located in Wyoming and Utah. These assets were impaired to estimated fair values of $112.2 million. The Partnership assesses whether events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. The fair value of assets with impairment triggers were measured using the income approach and Level-3 fair value inputs. The income approach was based on the Partnership’s projected future earnings before interest, taxes, depreciation, and amortization (“EBITDA”) and free cash flows, which requires significant assumptions including, among others, future throughput volumes based on current expectations of producer activity and operating costs. These impairments were primarily triggered by reductions in estimated future cash flows resulting from lower forecasted producer throughput and lower commodity prices. The remaining impairments of $16.5 million were primarily at the DJ Basin complex due to cancellation of projects and impairments of rights-of-way. During the year ended December 31, 2019, the Partnership recognized impairments of $6.3 million, primarily at the DJ Basin complex due to impairments of rights-of-way and cancellation of projects. Potential future long-lived asset impairments. As of June 30, 2020, it is reasonably possible that prolonged low commodity prices, further commodity-price declines, and changes to producers’ drilling plans in response to lower prices could result in future long-lived asset impairments.

Goodwill

Goodwill	6 Months Ended
	Jun. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	9. GOODWILL Goodwill is recorded when the purchase price of a business acquired exceeds the fair market value of the tangible and separately measurable intangible net assets. Goodwill also includes the allocated historic carrying value of midstream goodwill attributed to the Partnership’s assets previously acquired from Anadarko. The Partnership’s goodwill has been allocated to two reporting units: (i) gathering and processing and (ii) transportation. The Partnership evaluates goodwill for impairment annually, as of October 1, or more often as facts and circumstances warrant. An initial qualitative assessment is performed to determine the likelihood of whether goodwill is impaired and if deemed necessary based on this assessment, a quantitative assessment is then performed. If the quantitative assessment indicates that the carrying amount of the reporting unit, including goodwill, exceeds its fair value, a goodwill impairment is recorded for the amount by which the reporting unit’s carrying value exceeds its fair value. During the three months ended March 31, 2020, the Partnership performed an interim goodwill impairment test due to a significant decline in the trading price of the Partnership’s common units, triggered by the combined impacts from the global outbreak of COVID-19 and the oil-market disruption resulting from significantly lower global demand and corresponding oversupply of crude oil. The Partnership primarily used the market approach and Level-3 inputs to estimate the fair value of its two reporting units. The market approach was based on multiples of EBITDA and the Partnership’s projected future EBITDA. The EBITDA multiples were based on current and historic multiples for comparable midstream companies of similar size and business profit to the Partnership. The EBITDA projections require significant assumptions including, among others, future throughput volumes based on current expectations of producer activity and operating costs. The reasonableness of the market approach was tested against an income approach that was based on a discounted cash-flow analysis. Key assumptions in this analysis include the use of an appropriate discount rate, terminal-year multiples, and estimated future cash flows, including estimates of throughput, capital expenditures, operating, and general and administrative costs. The Partnership also reviewed the reasonableness of the total fair value of both reporting units to the market capitalization as of March 31, 2020, and the reasonableness of an implied acquisition premium. Impairment determinations involve significant assumptions and judgments, and differing assumptions regarding any of these inputs could have a significant effect on the valuations. As a result of the interim impairment test, the Partnership recognized a goodwill impairment of $441.0 million during the first quarter of 2020, which reduced the carrying amount of goodwill to zero for the gathering and processing reporting unit. Goodwill allocated to the transportation reporting unit of $4.8 million as of March 31, 2020, was not impaired.

Components of Working Capital

Components of Working Capital	6 Months Ended
	Jun. 30, 2020
Components Of Working Capital [Abstract]
Components of Working Capital	10. COMPONENTS OF WORKING CAPITAL A summary of accounts receivable, net is as follows: The Partnership WES Operating thousands June 30, December 31, June 30, December 31, Trade receivables, net $ 457,405 $ 260,458 $ 431,388 $ 260,694 Other receivables, net 2,913 54 2,882 54 Total accounts receivable, net $ 460,318 $ 260,512 $ 434,270 $ 260,748 A summary of other current assets is as follows: The Partnership WES Operating thousands June 30, December 31, June 30, December 31, NGLs inventory $ 559 $ 906 $ 559 $ 906 Materials and supplies inventory — 23,444 — 23,444 Imbalance receivables 7,985 4,690 7,985 4,690 Prepaid insurance 1,877 5,676 495 3,652 Contract assets 15,084 7,129 15,084 7,129 Other 13,602 93 13,602 93 Total other current assets $ 39,107 $ 41,938 $ 37,725 $ 39,914 A summary of accrued liabilities is as follows: The Partnership WES Operating thousands June 30, December 31, June 30, December 31, Accrued interest expense $ 130,921 $ 72,064 $ 130,921 $ 72,064 Short-term asset retirement obligations 27,662 22,472 27,662 22,472 Short-term remediation and reclamation obligations 3,528 3,528 3,528 3,528 Income taxes payable 662 697 662 697 Contract liabilities 9,231 19,659 9,231 19,659 Other (1) 45,221 31,373 21,914 31,219 Total accrued liabilities $ 217,225 $ 149,793 $ 193,918 $ 149,639 (1) Includes amounts related to WES Operating’s interest-rate swap agreements as of June 30, 2020, and December 31, 2019 (see Note 11 ).

Debt and Interest Expense

Debt and Interest Expense	6 Months Ended
	Jun. 30, 2020
Debt Instruments [Abstract]
Debt and Interest Expense	11. DEBT AND INTEREST EXPENSE WES Operating is the borrower for all outstanding debt and is expected to be the borrower for all future debt issuances. The following table presents the outstanding debt: June 30, 2020 December 31, 2019 thousands Principal Carrying Fair Value (1) Principal Carrying Fair Value (1) Short-term debt 5.375% Senior Notes due 2021 $ 431,081 $ 430,049 $ 437,442 $ — $ — $ — Finance lease liabilities (2) 8,570 8,570 8,570 7,873 7,873 7,873 Total short-term debt $ 439,651 $ 438,619 $ 446,012 $ 7,873 $ 7,873 $ 7,873 Long-term debt 5.375% Senior Notes due 2021 $ — $ — $ — $ 500,000 $ 498,168 $ 515,042 4.000% Senior Notes due 2022 584,417 583,937 580,390 670,000 669,322 689,784 Floating-Rate Senior Notes due 2023 289,978 288,322 274,219 — — — 3.100% Senior Notes due 2025 1,000,000 992,109 954,941 — — — 3.950% Senior Notes due 2025 500,000 494,343 470,309 500,000 493,830 504,968 4.650% Senior Notes due 2026 500,000 496,450 481,202 500,000 496,197 513,393 4.500% Senior Notes due 2028 400,000 395,362 379,742 400,000 395,113 390,920 4.750% Senior Notes due 2028 400,000 396,370 384,618 400,000 396,190 400,962 4.050% Senior Notes due 2030 1,200,000 1,188,951 1,160,136 — — — 5.450% Senior Notes due 2044 600,000 593,533 501,525 600,000 593,470 533,710 5.300% Senior Notes due 2048 700,000 686,944 573,902 700,000 686,843 610,841 5.500% Senior Notes due 2048 350,000 342,487 289,423 350,000 342,432 310,198 5.250% Senior Notes due 2050 1,000,000 983,411 873,172 — — — RCF 75,000 75,000 75,000 380,000 380,000 380,000 Term loan facility — — — 3,000,000 3,000,000 3,000,000 Finance lease liabilities 27,177 27,177 27,177 — — — Total long-term debt $ 7,626,572 $ 7,544,396 $ 7,025,756 $ 8,000,000 $ 7,951,565 $ 7,849,818 (1) Fair value is measured using the market approach and Level-2 fair value inputs. (2) Includes related-party amounts as of December 31, 2019. 11. DEBT AND INTEREST EXPENSE (CONTINUED) Debt activity. The following table presents the debt activity for the six months ended June 30, 2020: thousands Carrying Value Balance at December 31, 2019 $ 7,959,438 RCF borrowings 125,000 Issuance of Floating-Rate Senior Notes due 2023 300,000 Issuance of 3.100% Senior Notes due 2025 1,000,000 Issuance of 4.050% Senior Notes due 2030 1,200,000 Issuance of 5.250% Senior Notes due 2050 1,000,000 Finance lease liabilities 27,875 Repayments of RCF borrowings (430,000) Repayment of Term loan facility borrowings (3,000,000) Repayment of 5.375% Senior Notes due 2021 (68,919) Repayment of 4.000% Senior Notes due 2022 (85,583) Repayment of Floating-Rate Senior Notes due 2023 (10,022) Other (34,774) Balance at June 30, 2020 $ 7,983,015 WES Operating Senior Notes. In January 2020, WES Operating issued the following notes: • Fixed-Rate 3.100% Senior Notes due 2025, 4.050% Senior Notes due 2030, and 5.250% Senior Notes due 2050, offered to the public at prices of 99.962%, 99.900%, and 99.442%, respectively, of the face amount (collectively referred to as the “Fixed-Rate Senior Notes”). Including the effects of the issuance and underwriting discounts, the effective interest rates of the Senior Notes due 2025, 2030, and 2050, are 3.287%, 4.168%, and 5.362%, respectively. Interest is paid on each such series semi-annually on February 1 and August 1 of each year, beginning August 1, 2020; and • Floating-Rate Senior Notes due 2023 (the “Floating-Rate Senior Notes”). As of June 30, 2020, the interest rate on the Floating-Rate Senior Notes was 2.66%. Interest is paid quarterly in arrears on January 13, April 13, July 13, and October 13 of each year. Interest is determined at a benchmark rate (which is initially a three-month London Interbank Offered Rate) on the interest determination date plus 0.85%. Net proceeds from the Fixed-Rate Senior Notes and Floating-Rate Senior Notes were used to repay the $3.0 billion in outstanding borrowings under the Term loan facility and outstanding amounts under the RCF, and for general partnership purposes. The interest payable on each of the Fixed-Rate Senior Notes and Floating-Rate Senior Notes is subject to adjustment from time to time if the credit rating assigned to such notes declines below certain specified levels or if credit-rating downgrades are subsequently followed by credit-rating upgrades. In March 2020, Fitch Ratings (“Fitch”) and Standard and Poor’s (“S&P”) downgraded WES Operating’s long-term debt from “BBB-” to “BB+.” In May 2020, Fitch downgraded WES Operating’s long-term debt to “BB” and in June 2020, Moody’s Investors Service downgraded WES Operating’s long-term debt from “Ba1” to “Ba2.” As a result of these downgrades, annualized borrowing costs will increase by $35.0 million. 11. DEBT AND INTEREST EXPENSE (CONTINUED) During the first quarter of 2020, WES Operating purchased and retired $61.4 million of the 5.375% Senior Notes due 2021 and $38.6 million of the 4.000% Senior Notes due 2022 via open-market repurchases. During the second quarter of 2020, WES Operating purchased and retired (i) an additional $7.5 million of the 5.375% Senior Notes due 2021 and $47.0 million of the 4.000% Senior Notes due 2022, and (ii) $10.0 million of the Floating-Rate Senior Notes, each via open-market repurchases. For the three and six months ended June 30, 2020, gains of $1.4 million and $11.0 million, respectively, were recognized for the early retirement of these notes. As of June 30, 2020, the 5.375% Senior Notes due 2021 were classified as short-term debt on the consolidated balance sheet. At June 30, 2020, WES Operating was in compliance with all covenants under the relevant governing indentures. WGP RCF. The WGP RCF, which previously was available to purchase WES Operating common units and for general partnership purposes, matured in March 2019 and the $28.0 million of outstanding borrowings were repaid. Revolving credit facility. In December 2019, WES Operating entered into an amendment to the RCF, which is expandable to a maximum of $2.5 billion, to, among other things, exercise the final one-year extension option to extend the maturity date of the RCF from February 2024 to February 2025, for each extending lender. The maturity date with respect to each non-extending lender, whose commitments represent $100.0 million out of $2.0 billion of total commitments from all lenders, remains February 2024. See Note 1 . As of June 30, 2020, there were $75.0 million of outstanding borrowings and $5.0 million of outstanding letters of credit, resulting in $1.9 billion of available borrowing capacity under the RCF. As of June 30, 2020 and 2019, the interest rate on any outstanding RCF borrowings was 1.66% and 3.71%, respectively. The facility-fee rate was 0.25% and 0.20% at June 30, 2020 and 2019, respectively. At June 30, 2020, WES Operating was in compliance with all covenants under the RCF. As a result of credit-rating downgrades received from Fitch and S&P (see WES Operating Senior Notes above), beginning in the second quarter of 2020, the interest rate on outstanding RCF borrowings increased by 0.20% and the RCF facility-fee rate increased by 0.05%, from 0.20% to 0.25%. Term loan facility. In December 2018, WES Operating entered into the Term loan facility, the proceeds from which were used to fund substantially all of the cash portion of the consideration under the Merger Agreement and the payment of related transaction costs (see Note 1 ). As of June 30, 2019, the interest rate on the outstanding borrowings was 3.78%. In January 2020, WES Operating repaid the outstanding borrowings with proceeds from the issuance of the Fixed-Rate Senior Notes and Floating-Rate Senior Notes and terminated the Term loan facility (see WES Operating Senior Notes above). During the first quarter of 2020, a loss of $2.3 million was recognized for the early termination of the Term loan facility. Finance lease liabilities. The Partnership subleased equipment from Occidental via finance leases through April 2020. During the first quarter of 2020, the Partnership entered into finance leases with third parties for equipment and vehicles extending through 2029, with future lease payments of $41.3 million as of June 30, 2020. APCWH Note Payable. In June 2017, in connection with funding the construction of the APC water systems that were acquired as part of the AMA acquisition, APCWH entered into an eight-year note payable agreement with Anadarko. This note payable had a maximum borrowing limit of $500.0 million, including accrued interest. The APCWH Note Payable was repaid at Merger completion. See Note 1 . Interest-rate swaps. In December 2018 and March 2019, WES Operating entered into interest-rate swap agreements with an aggregate notional principal amount of $750.0 million and $375.0 million, respectively, to manage interest-rate risk associated with anticipated debt issuances. In November and December 2019, WES Operating entered into additional interest-rate swap agreements with an aggregate notional principal amount of $1,125.0 million, effectively offsetting the swap agreements entered into in December 2018 and March 2019. 11. DEBT AND INTEREST EXPENSE (CONTINUED) In December 2019, all outstanding interest-rate swap agreements were settled. As part of the settlement, WES Operating made cash payments of $107.7 million and recorded an accrued liability of $25.6 million to be paid quarterly in 2020. For the six months ended June 30, 2020, WES Operating made cash payments of $12.8 million. These cash payments were classified as cash flows from operating activities in the consolidated statements of cash flows. The Partnership did not apply hedge accounting and, therefore, gains and losses associated with the interest-rate swap agreements were recognized in earnings. For the three and six months ended June 30, 2019, non-cash losses of $59.0 million and $94.6 million, respectively, were recognized, which are included in Other income (expense), net in the consolidated statements of operations. Interest expense. The following table summarizes the amounts included in interest expense: Three Months Ended Six Months Ended thousands 2020 2019 2020 2019 Third parties Long-term and short-term debt $ (89,650) $ (82,624) $ (179,419) $ (149,720) Finance lease liabilities (388) — (793) — Amortization of debt issuance costs and commitment fees (3,462) (3,170) (6,589) (6,322) Capitalized interest (1,154) 6,342 3,604 12,547 Total interest expense – third parties (94,654) (79,452) (183,197) (143,495) Related parties APCWH Note Payable — — — (1,833) Finance lease liabilities — (20) (43) (20) Total interest expense – related parties — (20) (43) (1,853) Interest expense $ (94,654) $ (79,472) $ (183,240) $ (145,348)

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	12. COMMITMENTS AND CONTINGENCIES Litigation and legal proceedings. 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 the 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, and those of its unconsolidated related parties, the majority of which is expected to be paid in the next twelve months. These commitments primarily relate to construction and expansion projects at the West Texas and DJ Basin complexes, DBM water systems, and DBM oil system.

Description of Business and B_2

Description of Business and Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Consolidation policy	Basis of presentation. The consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”). The consolidated financial statements include the accounts of the Partnership and entities in which it holds a controlling financial interest, including WES Operating and WES Operating GP. All significant intercompany transactions have been eliminated. The following table outlines the ownership interests and the accounting method of consolidation used in the consolidated financial statements for entities not wholly owned: Percentage Interest Full consolidation Chipeta (1) 75.00 % Proportionate consolidation (2) Springfield system 50.10 % Marcellus Interest systems 33.75 % Equity investments (3) Mi Vida 50.00 % Ranch Westex 50.00 % FRP 33.33 % Red Bluff Express 30.00 % Mont Belvieu JV 25.00 % Rendezvous 22.00 % TEP 20.00 % TEG 20.00 % Whitethorn LLC 20.00 % Saddlehorn 20.00 % Cactus II 15.00 % Panola 15.00 % Fort Union 14.81 % White Cliffs 10.00 % (1) The 25% third-party interest in Chipeta Processing LLC (“Chipeta”) is reflected within noncontrolling interests in the consolidated financial statements. See Noncontrolling interests below. (2) The Partnership proportionately consolidates its associated share of the assets, liabilities, revenues, and expenses attributable to these assets. (3) Investments in non-controlled entities over which the Partnership exercises significant influence are accounted for under the equity method of accounting. “Equity-investment throughput” refers to the Partnership’s share of average throughput for these investments. 1. DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (CONTINUED) The consolidated financial results of WES Operating are included in the Partnership’s consolidated financial statements. Throughout these notes to consolidated financial statements, and to the extent material, any differences between the consolidated financial results of the Partnership and WES Operating are discussed separately. The Partnership’s consolidated financial statements differ from those of WES Operating primarily as a result of (i) the presentation of noncontrolling interest ownership (see Noncontrolling interests below and Note 5 ), (ii) the elimination of WES Operating GP’s investment in WES Operating with WES Operating GP’s underlying capital account, (iii) the general and administrative expenses incurred by the Partnership, which are separate from, and in addition to, those incurred by WES Operating, (iv) the inclusion of the impact of Partnership equity balances and Partnership distributions, and (v) the senior secured revolving credit facility (“WGP RCF”) until its repayment in March 2019. See Note 11 . Noncontrolling interests. For periods subsequent to Merger completion, the Partnership’s noncontrolling interests in the consolidated financial statements consist of (i) the 25% third-party interest in Chipeta and (ii) the 2.0% Occidental subsidiary-owned limited partner interest in WES Operating. For periods prior to Merger completion, the Partnership’s noncontrolling interests in the consolidated financial statements consisted of (i) the 25% third-party interest in Chipeta, (ii) the publicly held limited partner interests in WES Operating, (iii) the common units issued by WES Operating to subsidiaries of Anadarko as part of the consideration paid for prior-period acquisitions from Anadarko, and (iv) the Class C units issued by WES Operating to a subsidiary of Anadarko as part of the funding for the acquisition of DBM. For all periods presented, WES Operating’s noncontrolling interest in the consolidated financial statements consists of the 25% third-party interest in Chipeta. See Note 5. When WES Operating issues equity, the carrying amount of the noncontrolling interest reported by the Partnership is adjusted to reflect the noncontrolling ownership interest in WES Operating. The resulting impact of such noncontrolling interest adjustment on the Partnership’s interest in WES Operating is reflected as an adjustment to the Partnership’s partners’ capital.
Business combinations policy	Presentation of the Partnership’s assets. The Partnership’s assets include assets owned and ownership interests accounted for by the Partnership under the equity method of accounting, through its 98.0% partnership interest in WES Operating as of June 30, 2020 (see Note 7 ). The Partnership also owns and controls the entire non-economic general partner interest in WES Operating GP, and the Partnership’s general partner is owned by Occidental.
Use of estimates policy	Use of estimates. 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 reasonable methods. 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 included 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.
Inventory policy	Inventory. The cost of NGLs inventory is determined by the weighted-average cost method on a location-by-location basis. Inventory is stated at the lower of weighted-average cost or net realizable value. NGLs inventory is reported in Other current assets and NGLs line-fill inventory is reported in Other assets on the consolidated balance sheets. Materials and supplies inventory is valued at weighted-average cost and is reviewed periodically for obsolescence. As of June 30, 2020, materials and supplies inventory, previously reported in Other current assets, is prospectively reported in Other assets on the consolidated balance sheets. See Note 10 .
Segments policy	Segments. The Partnership’s operations continue to be organized into a single operating segment, the assets of which gather, compress, treat, process, and transport natural gas; gather, stabilize, and transport condensate, NGLs, and crude oil; and gather and dispose of produced water in the United States.
Equity-based compensation policy	Equity-based compensation. On February 10, 2020, the Board of Directors approved awards of phantom units (the “Awards”) to the Partnership’s executive officers under the Western Gas Equity Partners, LP 2012 Long-Term Incentive Plan (“WES LTIP”). The Awards include (i) an award of time-vested phantom units that vest ratably over a three-year period (“Time-Based Awards”), (ii) a market award that vests after a three-year performance period based on the Partnership’s relative total unitholder return as compared to a group of peer companies (“TUR Awards”), and (iii) a performance award that vests based on the Partnership’s average return on assets over a three-year performance period (“ROA Awards”). At vesting, the value of the TUR Awards and the ROA Awards will be determined in accordance with the terms of the respective Award Agreements that provide for payout percentages ranging from 0% to 200% based on results achieved over the applicable performance period. At vesting, the Awards generally will be settled in Partnership common units. Prior to vesting, the Awards pay in-kind distributions in the form of Partnership common units. The Partnership issued 21,090 common units as in-kind distributions under such Awards during the quarter ended June 30, 2020. In addition, phantom units are awarded under the WES LTIP to non-executive employees and independent directors of the Partnership from time to time, which vest ratably over a three-year period and one year from the grant date, respectively. Prior to vesting, the awards to non-executive employees and independent directors pay distribution equivalents in cash. The equity-based compensation expense attributable to these awards is amortized over the vesting periods applicable to the awards using the straight-line method. Expense is recognized based on the grant-date fair value and recorded, net of any forfeitures, as General and administrative expense in the consolidated statements of operations. The fair value of the Time-based Awards, ROA Awards, and non-executive awards is based on the observable market price of the Partnership’s units on the grant date of the award. The fair value of the TUR Awards is determined using a Monte Carlo simulation at the grant date of the award. For ROA Awards, all performance-related fair-value changes are recognized in compensation expense during the performance period. Compensation expense for the WES LTIP was $2.1 million and $3.2 million for the three and six months ended June 30, 2020, respectively, and $0.4 million for the three and six months ended June 30, 2019.
Defined-contribution plan policy	Defined-contribution plan. Beginning in the first quarter of 2020, employees of the Partnership are eligible to participate in the Western Midstream Savings Plan, a defined-contribution benefit plan maintained by the Partnership. All regular employees may participate in the plan by making elective contributions that are matched by the Partnership, subject to certain limitations. The Partnership also makes other contributions based on plan guidelines. The Partnership recognized expense related to the plan of $4.0 million and $4.4 million for the three and six months ended June 30, 2020, respectively, recorded as General and administrative expense in the consolidated statements of operations.
New accounting standards policy	Recently adopted accounting standards. Accounting Standards Update (“ASU”) 2016-13, Financial Instruments - Credit Losses (Topic 326) significantly changes the accounting and disclosure requirements related to credit losses on financial assets. Under the new standard, entities are now required to estimate lifetime expected credit losses for trade receivables, loans, and other financial instruments as of the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts, resulting in earlier recognition of credit losses. There was no impact to the consolidated financial statements with the Partnership’s adoption of the standard on January 1, 2020. The Partnership has implemented the necessary changes to its processes and controls to support accounting and disclosure requirements under this ASU. Accounts receivable and contract assets. Accounts receivable represent contractual rights for services performed, with, on average, 30-day payment terms from the date of invoice. Contract assets primarily relate to revenue accrued but not yet billed under cost-of-service contracts and accrued deficiency fees. As of June 30, 2020, there have been no negative indications regarding the collectability of significant receivables as it relates to impacts from the global outbreak of the coronavirus (“COVID-19”) and the oil-market disruption resulting from significantly lower global demand and corresponding oversupply of crude oil. The Partnership will continue to monitor the credit quality of its customer base and assess collectability of these assets as appropriate. Notes receivable. In May 2008, WES Operating 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 “Anadarko note receivable”). Following Occidental’s acquisition by merger of Anadarko in August 2019, Occidental became the ultimate counterparty. Since the first quarter of 2020, the Partnership has assessed the recoverability of the Anadarko note receivable under the loss-given-default method using historical data from internal and external sources, current market conditions, and reasonable and supportable forecasted information. The loss-given-default method was based on applicable probability of default percentages for similar debt instruments and the fair value of the Anadarko note receivable, which reflects an analysis of Occidental’s yield based on quoted market yields of similar Occidental debt instruments. As of June 30, 2020, the Partnership recognized an allowance for expected credit losses of $0.5 million related to the Anadarko note receivable. See Note 6 .
Net income (loss) per common unit policy	Partnership’s net income (loss) per common unit. Following the transactions contemplated by the Exchange Agreement, the common and general partner unitholders’ allocation of net income (loss) attributable to the Partnership was equal to their cash distributions plus their respective allocations of undistributed earnings or losses using the two-class method. Specifically, net income equal to the amount of available cash (as defined by the partnership agreement) was allocated to the common and general partner unitholders consistent with actual cash distributions and capital account allocations. Undistributed earnings (net income in excess of distributions) or undistributed losses (available cash in excess of net income (loss)) were then allocated to the common and general partner unitholders in accordance with their weighted-average ownership percentage during each period. The Partnership’s basic net income (loss) per common unit is calculated by dividing the limited partners’ interest in net income (loss) by the weighted-average number of common units outstanding during the period. Net income (loss) attributable to assets acquired from Anadarko for periods prior to the acquisition of such assets was not allocated to the limited partners when calculating net income (loss) per common unit. WES Operating’s net income (loss) per common unit. For periods subsequent to the closing of the Merger, net income (loss) per common unit for WES Operating is not calculated because no publicly traded units remained outstanding subsequent to the closing of the Merger.
Goodwill policy	Goodwill is recorded when the purchase price of a business acquired exceeds the fair market value of the tangible and separately measurable intangible net assets. Goodwill also includes the allocated historic carrying value of midstream goodwill attributed to the Partnership’s assets previously acquired from Anadarko. The Partnership’s goodwill has been allocated to two reporting units: (i) gathering and processing and (ii) transportation. The Partnership evaluates goodwill for impairment annually, as of October 1, or more often as facts and circumstances warrant. An initial qualitative assessment is performed to determine the likelihood of whether goodwill is impaired and if deemed necessary based on this assessment, a quantitative assessment is then performed. If the quantitative assessment indicates that the carrying amount of the reporting unit, including goodwill, exceeds its fair value, a goodwill impairment is recorded for the amount by which the reporting unit’s carrying value exceeds its fair value.
Derivatives policy	The Partnership did not apply hedge accounting and, therefore, gains and losses associated with the interest-rate swap agreements were recognized in earnings. For the three and six months ended June 30, 2019, non-cash losses of $59.0 million and $94.6 million, respectively, were recognized, which are included in Other income (expense), net in the consolidated statements of operations.

Description of Business and B_3

Description of Business and Basis of Presentation (Tables)	6 Months Ended
	Jun. 30, 2020
Accounting Policies [Abstract]
Assets and Investments Table	As of June 30, 2020, the Partnership’s assets and investments consisted of the following: Wholly Operated Non-Operated Equity Gathering systems (1) 17 2 3 2 Treating facilities 38 3 — 3 Natural-gas processing plants/trains 26 3 — 5 NGLs pipelines 2 — — 4 Natural-gas pipelines 5 — — 1 Crude-oil pipelines 3 1 — 3 (1) Includes the DBM water systems.
Ownership Interests and Method of Consolidation Table	The following table outlines the ownership interests and the accounting method of consolidation used in the consolidated financial statements for entities not wholly owned: Percentage Interest Full consolidation Chipeta (1) 75.00 % Proportionate consolidation (2) Springfield system 50.10 % Marcellus Interest systems 33.75 % Equity investments (3) Mi Vida 50.00 % Ranch Westex 50.00 % FRP 33.33 % Red Bluff Express 30.00 % Mont Belvieu JV 25.00 % Rendezvous 22.00 % TEP 20.00 % TEG 20.00 % Whitethorn LLC 20.00 % Saddlehorn 20.00 % Cactus II 15.00 % Panola 15.00 % Fort Union 14.81 % White Cliffs 10.00 % (1) The 25% third-party interest in Chipeta Processing LLC (“Chipeta”) is reflected within noncontrolling interests in the consolidated financial statements. See Noncontrolling interests below. (2) The Partnership proportionately consolidates its associated share of the assets, liabilities, revenues, and expenses attributable to these assets. (3) Investments in non-controlled entities over which the Partnership exercises significant influence are accounted for under the equity method of accounting. “Equity-investment throughput” refers to the Partnership’s share of average throughput for these investments.

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	6 Months Ended
	Jun. 30, 2020
Revenue from Contract with Customer [Abstract]
Summary of Revenue from Contracts with Customers Table	The following table summarizes revenue from contracts with customers: Three Months Ended Six Months Ended thousands 2020 2019 2020 2019 Revenue from customers Service revenues – fee based $ 581,452 $ 593,544 $ 1,223,373 $ 1,173,518 Service revenues – product based 7,000 16,675 22,921 36,054 Product sales 21,736 74,469 78,385 147,269 Total revenue from customers 610,188 684,688 1,324,679 1,356,841 Revenue from other than customers Lease revenue (1) 61,176 — 120,651 — Net gains (losses) on commodity-price swap agreements — — — (667) Other 391 366 738 763 Total revenues and other $ 671,755 $ 685,054 $ 1,446,068 $ 1,356,937 (1) For the three and six months ended June 30, 2020, includes fixed- and variable-lease revenue from an operating and maintenance agreement entered into with Occidental. See Operating lease within Note 6.
Contract Assets and Liabilities Activity Tables	The following table summarizes current-period activity related to contract assets from contracts with customers: thousands Balance at December 31, 2019 $ 67,357 Amounts transferred to Accounts receivable, net that were included in the contract assets balance at the beginning of the period (1) (2,592) Additional estimated revenues recognized (2) 9,646 Balance at June 30, 2020 $ 74,411 Contract assets at June 30, 2020 Other current assets $ 15,084 Other assets 59,327 Total contract assets from contracts with customers $ 74,411 (1) Includes $(2.6) million for the three months ended June 30, 2020. (2) Includes $4.3 million for the three months ended June 30, 2020. thousands Balance at December 31, 2019 $ 222,274 Cash received or receivable, excluding revenues recognized during the period (1) 23,902 Revenues recognized that were included in the contract liability balance at the beginning of the period (2) (10,533) Balance at June 30, 2020 $ 235,643 Contract liabilities at June 30, 2020 Accrued liabilities $ 9,231 Other liabilities 226,412 Total contract liabilities from contracts with customers $ 235,643 (1) Includes $12.7 million for the three months ended June 30, 2020. (2) Includes $(1.6) million for the three months ended June 30, 2020.
Expected Revenue Recognition from Satisfaction of Performance Obligations Table	Therefore, the following table represents only a portion of expected future revenues from existing contracts as most future revenues from customers are dependent on future variable customer volumes and, in some cases, variable commodity prices for those volumes. thousands Remainder of 2020 $ 387,163 2021 779,043 2022 1,033,556 2023 977,039 2024 946,468 Thereafter 3,551,258 Total $ 7,674,527

Partnership Distributions (Tabl

Partnership Distributions (Tables)	6 Months Ended
	Jun. 30, 2020
Distributions Made to Members or Limited Partners [Abstract]
Cash Distributions Tables	The Board of Directors of the general partner (the “Board of Directors”) declared the following cash distributions to the Partnership’s unitholders for the periods presented: thousands except per-unit amounts Quarters Ended Total Quarterly Total Quarterly Distribution 2019 March 31 $ 0.61000 $ 276,324 May 2019 June 30 0.61800 279,959 August 2019 September 30 0.62000 280,880 November 2019 December 31 0.62200 281,786 February 2020 2020 March 31 $ 0.31100 $ 140,893 May 2020 June 30 (1) 0.31100 140,900 August 2020 (1) The Board of Directors declared a cash distribution to the Partnership’s unitholders for the second quarter of 2020 of $0.31100 per unit, or $140.9 million in aggregate. The cash distribution is payable on August 13, 2020 to unitholders of record at the close of business on July 31, 2020, including the general partner units that were issued on December 31, 2019 (see Note 1 ). WES Operating made the following cash distributions to its limited partners for the periods presented: thousands Quarters Ended Total Quarterly 2019 March 31 $ 283,271 June 30 288,083 September 30 289,676 December 31 290,314 2020 March 31 $ 143,404 June 30 143,404

Related-Party Transactions (Tab

Related-Party Transactions (Tables)	6 Months Ended
	Jun. 30, 2020
Related Party Transaction [Line Items]
Related-Party Transactions Tables	The following tables summarize material related-party transactions included in the Partnership’s consolidated financial statements: Consolidated statements of operations Three Months Ended Six Months Ended thousands 2020 2019 2020 2019 Revenues and other Service revenues – fee based $ 460,138 $ 343,484 $ 907,921 $ 670,126 Service revenues – product based 1,168 634 4,146 1,986 Product sales 12,136 41,066 43,760 91,509 Total revenues and other 473,442 385,184 955,827 763,621 Equity income, net – related parties (1) 54,415 63,598 115,762 121,590 Operating expenses Cost of product 5,967 68,225 83,870 124,397 Operation and maintenance 1,516 32,318 34,357 71,459 General and administrative (2) 10,994 26,892 32,849 45,786 Total operating expenses 18,477 127,435 151,076 241,642 Interest income – Anadarko note receivable 4,225 4,225 8,450 8,450 Interest expense — (20) (43) (1,853) (1) See Note 7 . (2) Includes amounts charged by Occidental pursuant to the shared services agreements (see Shared services agreements within this Note 6 ). Also see Incentive Plans within this Note 6. Consolidated balance sheets thousands June 30, December 31, Assets Accounts receivable, net (1) $ 325,349 $ 113,345 Other current assets 13,019 4,982 Anadarko note receivable 259,481 260,000 Equity investments (2) 1,280,047 1,285,717 Other assets 59,302 60,221 Total assets 1,937,198 1,724,265 Liabilities Accounts and imbalance payables 655 — Short-term debt (3) — 7,873 Accrued liabilities 2,513 3,087 Other liabilities 119,132 97,800 Total liabilities 122,300 108,760 (1) Increase attributable to the timing of certain related-party cash receipts. The Partnership received $141.8 million of the June 30, 2020, Accounts receivable, net balance by July 3, 2020. (2) See Note 7 . (3) Includes amounts related to finance leases (see Note 11 ) . 6. RELATED-PARTY TRANSACTIONS (CONTINUED) Consolidated statements of cash flows Six Months Ended thousands 2020 2019 Distributions from equity-investment earnings – related parties $ 124,156 $ 115,483 Acquisitions from related parties — (2,007,501) Contributions to equity investments - related parties (16,064) (77,333) Distributions from equity investments in excess of cumulative earnings – related parties 13,340 17,052 APCWH Note Payable borrowings — 11,000 Repayment of APCWH Note Payable — (439,595) Distributions to Partnership unitholders (1) (225,914) (255,885) Distributions to WES Operating unitholders (2) (8,676) (8,210) Net contributions from (distributions to) related parties 21,832 456,938 Above-market component of swap agreements with Anadarko — 7,407 Finance lease payments (6,382) — (1) Represents distributions paid to Occidental pursuant to the partnership agreement of the Partnership (see Note 4 and Note 5 ). (2) Represents distributions paid to certain subsidiaries of Occidental pursuant to WES Operating’s partnership agreement (see Note 4 and Note 5 ).
WES Operating [Member]
Related Party Transaction [Line Items]
Related-Party Transactions Tables	The following tables summarize material related-party transactions for WES Operating (which are included in the Partnership’s consolidated financial statements) to the extent the amounts differ from the Partnership’s consolidated financial statements: Consolidated statements of operations Three Months Ended Six Months Ended thousands 2020 2019 2020 2019 General and administrative (1) $ 11,168 $ 26,380 $ 32,906 $ 44,878 (1) Includes amounts charged by Occidental pursuant to the shared services agreements (see Shared services agreements within this Note 6 ). Also see Incentive Plans within this Note 6. Consolidated balance sheets thousands June 30, December 31, Accounts receivable, net $ 299,332 $ 113,581 Consolidated statements of cash flows Six Months Ended thousands 2020 2019 Distributions to WES Operating unitholders (1) $ (433,718) $ (448,173) (1) Represents distributions paid to the Partnership and certain subsidiaries of Occidental pursuant to WES Operating’s partnership agreement (see Note 4 and Note 5 ). For the six months ended June 30, 2019, includes distributions to the Partnership and a subsidiary of Occidental related to the repayment of the WGP RCF (see Note 11 ).

Equity Investments (Tables)

Equity Investments (Tables)	6 Months Ended
	Jun. 30, 2020
Equity Method Investments and Joint Ventures [Abstract]
Equity Investments Table	The following table presents the equity-investments activity for the six months ended June 30, 2020: thousands Balance at December 31, 2019 Equity Contributions Distributions Distributions in excess of cumulative earnings (1) Balance at June 30, 2020 Fort Union $ (610) $ (566) $ — $ — $ — $ (1,176) White Cliffs 45,877 4,368 993 (3,826) (679) 46,733 Rendezvous 32,964 187 — (1,158) (1,072) 30,921 Mont Belvieu JV 103,036 13,734 — (13,753) (2,897) 100,120 TEG 18,199 2,198 — (2,209) (1,356) 16,832 TEP 203,556 18,410 — (21,588) (592) 199,786 FRP 207,782 19,909 3,670 (21,340) (4,193) 205,828 Whitethorn LLC 161,665 19,957 278 (20,811) — 161,089 Cactus II 172,165 10,955 10,471 (11,092) — 182,499 Saddlehorn 112,855 12,223 — (13,644) — 111,434 Panola 21,783 984 — (984) (431) 21,352 Mi Vida 57,807 5,178 — (5,925) (478) 56,582 Ranch Westex 46,678 5,648 — (5,249) (705) 46,372 Red Bluff Express 101,960 2,577 652 (2,577) (937) 101,675 Total $ 1,285,717 $ 115,762 $ 16,064 $ (124,156) $ (13,340) $ 1,280,047 (1) Distributions in excess of cumulative earnings, classified as investing cash flows in the consolidated statements of cash flows, are calculated on an individual-investment basis.

Property, Plant, and Equipment

Property, Plant, and Equipment (Tables)	6 Months Ended
	Jun. 30, 2020
Property, Plant and Equipment [Abstract]
Property, Plant, and Equipment Table	A summary of the historical cost of property, plant, and equipment is as follows: thousands Estimated Useful Life June 30, December 31, Land N/A $ 9,708 $ 9,495 Gathering systems – pipelines 30 years 5,203,293 5,092,004 Gathering systems – compressors 15 years 2,033,154 1,929,377 Processing complexes and treating facilities 25 years 3,380,567 3,237,801 Transportation pipeline and equipment 6 to 45 years 171,069 173,572 Produced-water disposal systems 20 years 810,275 754,774 Assets under construction N/A 289,418 486,584 Other 3 to 40 years 702,238 672,064 Total property, plant, and equipment 12,599,722 12,355,671 Less accumulated depreciation 3,685,006 3,290,740 Net property, plant, and equipment $ 8,914,716 $ 9,064,931

Components of Working Capital (

Components of Working Capital (Tables)	6 Months Ended
	Jun. 30, 2020
Components Of Working Capital [Abstract]
Accounts Receivable, Net Table	A summary of accounts receivable, net is as follows: The Partnership WES Operating thousands June 30, December 31, June 30, December 31, Trade receivables, net $ 457,405 $ 260,458 $ 431,388 $ 260,694 Other receivables, net 2,913 54 2,882 54 Total accounts receivable, net $ 460,318 $ 260,512 $ 434,270 $ 260,748
Other Current Assets Table	A summary of other current assets is as follows: The Partnership WES Operating thousands June 30, December 31, June 30, December 31, NGLs inventory $ 559 $ 906 $ 559 $ 906 Materials and supplies inventory — 23,444 — 23,444 Imbalance receivables 7,985 4,690 7,985 4,690 Prepaid insurance 1,877 5,676 495 3,652 Contract assets 15,084 7,129 15,084 7,129 Other 13,602 93 13,602 93 Total other current assets $ 39,107 $ 41,938 $ 37,725 $ 39,914
Accrued Liabilities Table	A summary of accrued liabilities is as follows: The Partnership WES Operating thousands June 30, December 31, June 30, December 31, Accrued interest expense $ 130,921 $ 72,064 $ 130,921 $ 72,064 Short-term asset retirement obligations 27,662 22,472 27,662 22,472 Short-term remediation and reclamation obligations 3,528 3,528 3,528 3,528 Income taxes payable 662 697 662 697 Contract liabilities 9,231 19,659 9,231 19,659 Other (1) 45,221 31,373 21,914 31,219 Total accrued liabilities $ 217,225 $ 149,793 $ 193,918 $ 149,639 (1) Includes amounts related to WES Operating’s interest-rate swap agreements as of June 30, 2020, and December 31, 2019 (see Note 11 ).

Debt and Interest Expense (Tabl

Debt and Interest Expense (Tables)	6 Months Ended
	Jun. 30, 2020
Debt Instruments [Abstract]
Debt Outstanding and Debt Activity Tables	WES Operating is the borrower for all outstanding debt and is expected to be the borrower for all future debt issuances. The following table presents the outstanding debt: June 30, 2020 December 31, 2019 thousands Principal Carrying Fair Value (1) Principal Carrying Fair Value (1) Short-term debt 5.375% Senior Notes due 2021 $ 431,081 $ 430,049 $ 437,442 $ — $ — $ — Finance lease liabilities (2) 8,570 8,570 8,570 7,873 7,873 7,873 Total short-term debt $ 439,651 $ 438,619 $ 446,012 $ 7,873 $ 7,873 $ 7,873 Long-term debt 5.375% Senior Notes due 2021 $ — $ — $ — $ 500,000 $ 498,168 $ 515,042 4.000% Senior Notes due 2022 584,417 583,937 580,390 670,000 669,322 689,784 Floating-Rate Senior Notes due 2023 289,978 288,322 274,219 — — — 3.100% Senior Notes due 2025 1,000,000 992,109 954,941 — — — 3.950% Senior Notes due 2025 500,000 494,343 470,309 500,000 493,830 504,968 4.650% Senior Notes due 2026 500,000 496,450 481,202 500,000 496,197 513,393 4.500% Senior Notes due 2028 400,000 395,362 379,742 400,000 395,113 390,920 4.750% Senior Notes due 2028 400,000 396,370 384,618 400,000 396,190 400,962 4.050% Senior Notes due 2030 1,200,000 1,188,951 1,160,136 — — — 5.450% Senior Notes due 2044 600,000 593,533 501,525 600,000 593,470 533,710 5.300% Senior Notes due 2048 700,000 686,944 573,902 700,000 686,843 610,841 5.500% Senior Notes due 2048 350,000 342,487 289,423 350,000 342,432 310,198 5.250% Senior Notes due 2050 1,000,000 983,411 873,172 — — — RCF 75,000 75,000 75,000 380,000 380,000 380,000 Term loan facility — — — 3,000,000 3,000,000 3,000,000 Finance lease liabilities 27,177 27,177 27,177 — — — Total long-term debt $ 7,626,572 $ 7,544,396 $ 7,025,756 $ 8,000,000 $ 7,951,565 $ 7,849,818 (1) Fair value is measured using the market approach and Level-2 fair value inputs. (2) Includes related-party amounts as of December 31, 2019. 11. DEBT AND INTEREST EXPENSE (CONTINUED) Debt activity. The following table presents the debt activity for the six months ended June 30, 2020: thousands Carrying Value Balance at December 31, 2019 $ 7,959,438 RCF borrowings 125,000 Issuance of Floating-Rate Senior Notes due 2023 300,000 Issuance of 3.100% Senior Notes due 2025 1,000,000 Issuance of 4.050% Senior Notes due 2030 1,200,000 Issuance of 5.250% Senior Notes due 2050 1,000,000 Finance lease liabilities 27,875 Repayments of RCF borrowings (430,000) Repayment of Term loan facility borrowings (3,000,000) Repayment of 5.375% Senior Notes due 2021 (68,919) Repayment of 4.000% Senior Notes due 2022 (85,583) Repayment of Floating-Rate Senior Notes due 2023 (10,022) Other (34,774) Balance at June 30, 2020 $ 7,983,015
Interest Expense Table	The following table summarizes the amounts included in interest expense: Three Months Ended Six Months Ended thousands 2020 2019 2020 2019 Third parties Long-term and short-term debt $ (89,650) $ (82,624) $ (179,419) $ (149,720) Finance lease liabilities (388) — (793) — Amortization of debt issuance costs and commitment fees (3,462) (3,170) (6,589) (6,322) Capitalized interest (1,154) 6,342 3,604 12,547 Total interest expense – third parties (94,654) (79,452) (183,197) (143,495) Related parties APCWH Note Payable — — — (1,833) Finance lease liabilities — (20) (43) (20) Total interest expense – related parties — (20) (43) (1,853) Interest expense $ (94,654) $ (79,472) $ (183,240) $ (145,348)

Description of Business and B_4

Description of Business and Basis of Presentation - Assets and Investments Table (Details)	Jun. 30, 2020unit
Wholly Owned and Operated [Member] | Gathering Systems [Member]
Assets [Line Items]
Assets, number of units	17
Wholly Owned and Operated [Member] | Treating Facilities [Member]
Assets [Line Items]
Assets, number of units	38
Wholly Owned and Operated [Member] | Natural-Gas Processing Plants/Trains [Member]
Assets [Line Items]
Assets, number of units	26
Wholly Owned and Operated [Member] | Natural-Gas Liquids Pipelines [Member]
Assets [Line Items]
Assets, number of units	2
Wholly Owned and Operated [Member] | Natural-Gas Pipelines [Member]
Assets [Line Items]
Assets, number of units	5
Wholly Owned and Operated [Member] | Crude-Oil Pipelines [Member]
Assets [Line Items]
Assets, number of units	3
Operated Interests [Member] | Gathering Systems [Member]
Assets [Line Items]
Assets, number of units	2
Operated Interests [Member] | Treating Facilities [Member]
Assets [Line Items]
Assets, number of units	3
Operated Interests [Member] | Natural-Gas Processing Plants/Trains [Member]
Assets [Line Items]
Assets, number of units	3
Operated Interests [Member] | Crude-Oil Pipelines [Member]
Assets [Line Items]
Assets, number of units	1
Non-Operated Interests [Member] | Gathering Systems [Member]
Assets [Line Items]
Assets, number of units	3
Equity Interests [Member] | Gathering Systems [Member]
Assets [Line Items]
Assets, number of units	2
Equity Interests [Member] | Treating Facilities [Member]
Assets [Line Items]
Assets, number of units	3
Equity Interests [Member] | Natural-Gas Processing Plants/Trains [Member]
Assets [Line Items]
Assets, number of units	5
Equity Interests [Member] | Natural-Gas Liquids Pipelines [Member]
Assets [Line Items]
Assets, number of units	4
Equity Interests [Member] | Natural-Gas Pipelines [Member]
Assets [Line Items]
Assets, number of units	1
Equity Interests [Member] | Crude-Oil Pipelines [Member]
Assets [Line Items]
Assets, number of units	3

Description of Business and B_5

Description of Business and Basis of Presentation - Ownership Interests and Method of Consolidation Table (Details)	6 Months Ended
	Jun. 30, 2020
Chipeta [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership interest by noncontrolling interest owner	25.00%
Full Consolidation [Member] | Chipeta [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Percentage ownership interest	75.00%
Proportionate Consolidation [Member] | Springfield System [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Percentage ownership interest	50.10%
Proportionate Consolidation [Member] | Marcellus Interest Systems [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Percentage ownership interest	33.75%
Equity Investments [Member] | Mi Vida [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity investment ownership percentage	50.00%
Equity Investments [Member] | Ranch Westex [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity investment ownership percentage	50.00%
Equity Investments [Member] | Front Range Pipeline [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity investment ownership percentage	33.33%
Equity Investments [Member] | Red Bluff Express [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity investment ownership percentage	30.00%
Equity Investments [Member] | Mont Belvieu JV [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity investment ownership percentage	25.00%
Equity Investments [Member] | Rendezvous [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity investment ownership percentage	22.00%
Equity Investments [Member] | Texas Express Pipeline [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity investment ownership percentage	20.00%
Equity Investments [Member] | Texas Express Gathering [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity investment ownership percentage	20.00%
Equity Investments [Member] | Whitethorn LLC [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity investment ownership percentage	20.00%
Equity Investments [Member] | Saddlehorn [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity investment ownership percentage	20.00%
Equity Investments [Member] | Cactus II [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity investment ownership percentage	15.00%
Equity Investments [Member] | Panola [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity investment ownership percentage	15.00%
Equity Investments [Member] | Fort Union [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity investment ownership percentage	14.81%
Equity Investments [Member] | White Cliffs [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity investment ownership percentage	10.00%

Description of Business and B_6

Description of Business and Basis of Presentation - Additional Information (Details) - USD ($)		Dec. 31, 2019	May 31, 2008	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018	Jul. 01, 2019	Feb. 28, 2019
Common units outstanding		443,971,409		443,992,499				443,992,499
Revenues and other	[1]			$ 671,755,000		$ 685,054,000		$ 1,446,068,000	$ 1,356,937,000
Equity-based compensation - in-kind distributions				21,090
Defined-contribution plan expense				$ 4,000,000				$ 4,400,000
Maximum [Member]
Equity-based compensation - payout percentage								200.00%
Minimum [Member]
Equity-based compensation - payout percentage								0.00%
Executive Long-Term Incentive Plans [Member]
Units vesting period								3 years
Non-Executive Long-Term Incentive Plans [Member]
Units vesting period								3 years
Independent Director Long-Term Incentive Plans
Units vesting period								1 year
WES LTIP [Member]
Equity-based compensation expense				2,100,000		400,000		$ 3,200,000	400,000
Product Sales [Member]
Revenues and other				21,736,000		74,469,000		78,385,000	146,602,000
Related Parties [Member]
Revenues and other				473,442,000		385,184,000		955,827,000	763,621,000
Anadarko note receivable			$ 260,000,000
Anadarko note receivable - fixed annual rate			6.50%
Anadarko note receivable - allowance for expected credit loss				500,000				500,000
Related Parties [Member] | Product Sales [Member]
Revenues and other				$ 12,136,000		41,066,000		$ 43,760,000	91,509,000
Related Parties [Member] | Product Sales [Member] | Kitty Draw and Third Creek Gathering Systems [Member]
Revenues and other							$ 5,500,000			$ (10,900,000)
WES Operating [Member]
Ownership interest by noncontrolling interest owner				2.00%				2.00%
Chipeta [Member]
Ownership interest by noncontrolling interest owner				25.00%				25.00%
WES [Member] | WES Operating [Member]
Ownership interest								98.00%
Occidental [Member] | WES [Member]
Ownership interest								53.40%
General partner's interest		2.00%						2.00%
Common units outstanding				242,136,976				242,136,976
Occidental [Member] | WES [Member] | Common Units [Member]
Common units outstanding		9,060,641
Occidental [Member] | WES Operating [Member]
Ownership interest								2.00%
WES Operating [Member]
Cash contribution from related party					$ 20,000,000
Revenues and other	[2]			$ 671,755,000		685,054,000		$ 1,446,068,000	1,356,937,000
WES Operating [Member] | Product Sales [Member]
Revenues and other				21,736,000		74,469,000		78,385,000	146,602,000
WES Operating [Member] | Related Parties [Member]
Revenues and other				473,400,000		$ 385,200,000		955,800,000	$ 763,600,000
WES Operating [Member] | RCF [Member] | Revolving Credit Facility [Member]
Facility, maximum borrowing capacity				$ 2,000,000,000				$ 2,000,000,000				$ 2,000,000,000
WES Operating [Member] | Term Loan Facility [Member] | Revolving Credit Facility [Member]
Facility, maximum borrowing capacity											$ 3,000,000,000
[1]	Total revenues and other includes related-party amounts of $473.4 million and $955.8 million for the three and six months ended June 30, 2020, respectively, and $385.2 million and $763.6 million for the three and six months ended June 30, 2019, respectively. See Note 6 .
[2]	Total revenues and other includes related-party amounts of $473.4 million and $955.8 million for the three and six months ended June 30, 2020, respectively, and $385.2 million and $763.6 million for the three and six months ended June 30, 2019, respectively. See Note 6 .

Revenue from Contracts with C_3

Revenue from Contracts with Customers - Revenue From Contracts With Customers Table (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Revenue from customers		$ 610,188	$ 684,688	$ 1,324,679	$ 1,356,841
Revenue from other than customers, other		391	366	738	763
Total revenues and other	[1]	671,755	685,054	1,446,068	1,356,937
Service Revenues - Fee Based [Member]
Disaggregation of Revenue [Line Items]
Revenue from customers		581,452	593,544	1,223,373	1,173,518
Total revenues and other		642,628	593,544	1,344,024	1,173,518
Service Revenues - Product Based [Member]
Disaggregation of Revenue [Line Items]
Revenue from customers		7,000	16,675	22,921	36,054
Total revenues and other		7,000	16,675	22,921	36,054
Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from customers		21,736	74,469	78,385	147,269
Total revenues and other		21,736	74,469	78,385	146,602
Lease Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from other than customers		61,176	0	120,651	0
Commodity-Price Swap Agreements [Member]
Disaggregation of Revenue [Line Items]
Revenue from other than customers		$ 0	$ 0	$ 0	$ (667)
[1]	Total revenues and other includes related-party amounts of $473.4 million and $955.8 million for the three and six months ended June 30, 2020, respectively, and $385.2 million and $763.6 million for the three and six months ended June 30, 2019, respectively. See Note 6 .

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Contract Assets Table (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Change in Contracts with Customer, Asset [Roll Forward]
Balance at December 31, 2019		$ 67,357
Amounts transferred to Accounts receivable, net that were included in the contract assets balance at the beginning of the period	$ (2,600)	(2,592)
Additional estimated revenues recognized	4,300	9,646
Balance at June 30, 2020	74,411	74,411
Contract assets at June 30, 2020
Other current assets			$ 15,084	$ 7,129
Other assets			59,327
Total contract assets from contracts with customers	$ 74,411	$ 74,411	$ 74,411	$ 67,357

Revenue from Contracts with C_5

Revenue from Contracts with Customers - Contract Liabilities Table (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Change in Contracts with Customer, Liability [Roll Forward]
Balance at December 31, 2019		$ 222,274
Cash received or receivable, excluding revenues recognized during the period	$ 12,700	23,902
Revenues recognized that were included in the contract liability balance at the beginning of the period	(1,600)	(10,533)
Balance at June 30, 2020	235,643	235,643
Contract liabilities at June 30, 2020
Accrued liabilities			$ 9,231	$ 19,659
Other liabilities			226,412
Total contract liabilities from contracts with customers	$ 235,643	$ 235,643	$ 235,643	$ 222,274

Revenue from Contracts with C_6

Revenue from Contracts with Customers - Expected Revenues Table (Details) $ in Thousands	Jun. 30, 2020USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligation expected to be satisfied	$ 7,674,527
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligation expected to be satisfied	$ 387,163
Performance obligation expected to be satisfied, expected timing	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligation expected to be satisfied	$ 779,043
Performance obligation expected to be satisfied, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligation expected to be satisfied	$ 1,033,556
Performance obligation expected to be satisfied, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligation expected to be satisfied	$ 977,039
Performance obligation expected to be satisfied, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligation expected to be satisfied	$ 946,468
Performance obligation expected to be satisfied, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligation expected to be satisfied	$ 3,551,258
Performance obligation expected to be satisfied, expected timing

Revenue from Contracts with C_7

Revenue from Contracts with Customers - Additional Information (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Revenue from Contracts with Customer [Line Items]
Accounts receivable, net	$ 460,318	$ 260,512
Customers [Member]
Revenue from Contracts with Customer [Line Items]
Accounts receivable, net	$ 507,300	$ 362,600

Acquisitions and Divestitures -

Acquisitions and Divestitures - Additional Information (Details) - USD ($) $ in Millions	Feb. 28, 2019	Jan. 18, 2019	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019
Property, Plant and Equipment [Line Items]
Limited partner units			443,992,499	443,971,409
WES Operating [Member] | Anadarko [Member] | Common Units [Member]
Property, Plant and Equipment [Line Items]
Limited partner units					6,400,000
Mi Vida [Member]
Property, Plant and Equipment [Line Items]
Ownership percentage acquired	50.00%
Ranch Westex [Member]
Property, Plant and Equipment [Line Items]
Ownership percentage acquired	50.00%
Saddlehorn [Member]
Property, Plant and Equipment [Line Items]
Ownership percentage acquired	20.00%
Panola [Member]
Property, Plant and Equipment [Line Items]
Ownership percentage acquired	15.00%
Anadarko Midstream Assets [Member] | WES Operating [Member] | Common Units [Member]
Property, Plant and Equipment [Line Items]
Units issued	45,760,201
Anadarko Midstream Assets [Member] | WES Operating [Member] | Anadarko [Member] | Common Units [Member]
Property, Plant and Equipment [Line Items]
Limited partner units	6,375,284
Red Bluff Express [Member]
Property, Plant and Equipment [Line Items]
Ownership percentage acquired		30.00%
Acquisition, net investment		$ 92.5
Anadarko [Member] | Anadarko Midstream Assets [Member] | WES Operating [Member]
Property, Plant and Equipment [Line Items]
Cash payment for acquisition	$ 2,000

Partnership Distributions - Cas

Partnership Distributions - Cash Distributions Tables (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019
Distribution Made to Limited Partner [Line Items]
Total quarterly per-unit distribution	$ 0.31100	$ 0.31100	$ 0.62200	$ 0.62000	$ 0.61800	$ 0.61000
Total quarterly cash distribution	$ 140,900	$ 140,893	$ 281,786	$ 280,880	$ 279,959	$ 276,324
WES Operating [Member]
Distribution Made to Limited Partner [Line Items]
Total quarterly cash distribution	$ 143,404	$ 143,404	$ 290,314	$ 289,676	$ 288,083	$ 283,271

Partnership Distributions - Add

Partnership Distributions - Additional Information (Details) - shares	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019
Distribution Made to Limited Partner [Line Items]
Partnership agreement day requirement of distribution of available cash	55 days
Common units outstanding	443,992,499	443,971,409
WES Operating [Member] | Anadarko [Member] | Common Units [Member]
Distribution Made to Limited Partner [Line Items]
Common units outstanding			6,400,000
WES [Member] | Occidental [Member]
Distribution Made to Limited Partner [Line Items]
Distribution sharing percentage	2.00%
Common units outstanding	242,136,976
WES [Member] | Occidental [Member] | Common Units [Member]
Distribution Made to Limited Partner [Line Items]
Common units outstanding		9,060,641

Equity and Partners' Capital -

Equity and Partners' Capital - Additional Information (Details) - shares	Dec. 31, 2019	Nov. 30, 2014	Jun. 30, 2020	Feb. 28, 2019
Schedule of Investments [Line Items]
Common units outstanding	443,971,409		443,992,499
General partner units outstanding	9,060,641		9,060,641
WES [Member] | Public [Member]
Schedule of Investments [Line Items]
Common units outstanding			201,855,523
Limited partner's interest			44.60%
Occidental [Member] | WES [Member]
Schedule of Investments [Line Items]
Common units outstanding			242,136,976
Limited partner's interest			53.40%
General partner units outstanding			9,060,641
General partner's interest	2.00%		2.00%
Occidental [Member] | WES Operating [Member]
Schedule of Investments [Line Items]
Limited partner's interest			2.00%
WES [Member] | WES Operating [Member]
Schedule of Investments [Line Items]
Limited partner's interest			98.00%
WES Operating [Member] | Class C Units [Member]
Schedule of Investments [Line Items]
Class C units, common units issued upon conversion				1
WES Operating [Member] | Class C Units [Member] | Other Subsidiaries of Anadarko [Member]
Schedule of Investments [Line Items]
Units issued		10,913,853

Related-Party Transactions - Su

Related-Party Transactions - Summary of WES Related-Party Transactions Tables (Details) - USD ($)		Jul. 03, 2020	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Consolidated statements of operations [Abstract]
Revenues and other	[1]		$ 671,755,000	$ 685,054,000	$ 1,446,068,000	$ 1,356,937,000
Equity income, net – related parties			54,415,000	63,598,000	115,762,000	121,590,000
Cost of product			18,602,000	122,877,000	121,872,000	236,940,000
Operation and maintenance			145,186,000	148,431,000	304,377,000	291,260,000
General and administrative			36,423,000	30,027,000	76,888,000	52,871,000
Operating expenses	[2]		349,561,000	437,531,000	1,400,084,000	847,888,000
Interest income – Anadarko note receivable			4,225,000	4,225,000	8,450,000	8,450,000
Interest expense			(94,654,000)	(79,472,000)	(183,240,000)	(145,348,000)
Consolidated balance sheets [Abstract]
Accounts receivable, net			460,318,000		460,318,000		$ 260,512,000
Other current assets			39,107,000		39,107,000		41,938,000
Equity investments			1,280,047,000		1,280,047,000		1,285,717,000
Other assets	[3]		142,496,000		142,496,000		78,202,000
Total assets	[4]		11,953,243,000		11,953,243,000		12,346,453,000
Accounts and imbalance payables			181,563,000		181,563,000		293,128,000
Accrued liabilities			217,225,000		217,225,000		149,793,000
Other liabilities			234,615,000		234,615,000		208,346,000
Total liabilities	[5]		9,017,726,000		9,017,726,000		9,001,160,000
(Increase) decrease in accounts receivable, net					(200,136,000)	2,668,000
Consolidated statements of cash flows [Abstract]
Distributions from equity-investment earnings – related parties					124,156,000	115,483,000
Contributions to equity investments - related parties					(16,064,000)	(77,333,000)
Distributions from equity investments in excess of cumulative earnings – related parties					13,340,000	17,052,000
Distributions to Partnership unitholders	[6]				(422,679,000)	(408,234,000)
Net contributions from (distributions to) related parties					21,832,000	456,938,000
Above-market component of swap agreements with Anadarko	[6]				0	7,407,000
Finance lease payments	[7]				(10,262,000)	0
Service Revenues - Fee Based [Member]
Consolidated statements of operations [Abstract]
Revenues and other			642,628,000	593,544,000	1,344,024,000	1,173,518,000
Service Revenues - Product Based [Member]
Consolidated statements of operations [Abstract]
Revenues and other			7,000,000	16,675,000	22,921,000	36,054,000
Product Sales [Member]
Consolidated statements of operations [Abstract]
Revenues and other			21,736,000	74,469,000	78,385,000	146,602,000
Related Parties [Member]
Consolidated statements of operations [Abstract]
Revenues and other			473,442,000	385,184,000	955,827,000	763,621,000
Cost of product			5,967,000	68,225,000	83,870,000	124,397,000
Operation and maintenance			1,516,000	32,318,000	34,357,000	71,459,000
General and administrative			10,994,000	26,892,000	32,849,000	45,786,000
Operating expenses			18,477,000	127,435,000	151,076,000	241,642,000
Interest expense			0	(20,000)	(43,000)	(1,853,000)
Consolidated balance sheets [Abstract]
Accounts receivable, net			325,349,000		325,349,000		113,345,000
Other current assets			13,019,000		13,019,000		4,982,000
Anadarko note receivable			259,481,000		259,481,000		260,000,000
Other assets			59,302,000		59,302,000		60,221,000
Total assets			1,937,198,000		1,937,198,000		1,724,265,000
Accounts and imbalance payables			655,000		655,000		0
Short-term debt			0		0		7,873,000
Accrued liabilities			2,513,000		2,513,000		3,087,000
Other liabilities			119,132,000		119,132,000		97,800,000
Total liabilities			122,300,000		122,300,000		$ 108,760,000
Consolidated statements of cash flows [Abstract]
Acquisitions from related parties					0	(2,007,501,000)
APCWH Note Payable borrowings					0	11,000,000
Repayment of APCWH Note Payable					0	(439,595,000)
Distributions to Partnership unitholders					(225,914,000)	(255,885,000)
Finance lease payments					(6,382,000)	0
Related Parties [Member] | Subsequent Event [Member]
Consolidated balance sheets [Abstract]
(Increase) decrease in accounts receivable, net		$ 141,800,000
Related Parties [Member] | WES Operating [Member]
Consolidated statements of cash flows [Abstract]
Distributions to Partnership unitholders					(8,676,000)	(8,210,000)
Related Parties [Member] | Service Revenues - Fee Based [Member]
Consolidated statements of operations [Abstract]
Revenues and other			460,138,000	343,484,000	907,921,000	670,126,000
Related Parties [Member] | Service Revenues - Product Based [Member]
Consolidated statements of operations [Abstract]
Revenues and other			1,168,000	634,000	4,146,000	1,986,000
Related Parties [Member] | Product Sales [Member]
Consolidated statements of operations [Abstract]
Revenues and other			$ 12,136,000	$ 41,066,000	$ 43,760,000	$ 91,509,000
[1]	Total revenues and other includes related-party amounts of $473.4 million and $955.8 million for the three and six months ended June 30, 2020, respectively, and $385.2 million and $763.6 million for the three and six months ended June 30, 2019, respectively. See Note 6 .
[2]	Total operating expenses includes related-party amounts of $18.5 million and $151.1 million for the three and six months ended June 30, 2020, respectively, and $127.4 million and $241.6 million for the three and six months ended June 30, 2019, respectively. See Note 6 .
[3]	Other assets includes $3.2 million and $4.5 million of NGLs line-fill inventory as of June 30, 2020, and December 31, 2019, respectively. Other assets also includes $62.6 million of materials and supplies inventory as of June 30, 2020. See Note 1 .
[4]	Total assets includes related-party amounts of $1.9 billion and $1.7 billion as of June 30, 2020, and December 31, 2019, respectively, which includes related-party Accounts receivable, net of $325.3 million and $113.3 million as of June 30, 2020, and December 31, 2019, respectively. See Note 6 .
[5]	Total liabilities includes related-party amounts of $122.3 million and $108.8 million as of June 30, 2020, and December 31, 2019, respectively. See Note 6 .
[6]	See Note 6 .
[7]	For the six months ended June 30, 2020, includes related-party payments of $6.4 million.

Related-Party Transactions - _2

Related-Party Transactions - Summary of WES Operating Related-Party Transactions Tables (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Consolidated statements of operations [Abstract]
General and administrative		$ 36,423	$ 30,027	$ 76,888	$ 52,871
Consolidated balance sheets [Abstract]
Accounts receivable, net		460,318		460,318		$ 260,512
Consolidated statements of cash flows [Abstract]
Distributions to WES Operating unitholders	[1]			(422,679)	(408,234)
Related Parties [Member]
Consolidated statements of operations [Abstract]
General and administrative		10,994	26,892	32,849	45,786
Consolidated balance sheets [Abstract]
Accounts receivable, net		325,349		325,349		113,345
Consolidated statements of cash flows [Abstract]
Distributions to WES Operating unitholders				(225,914)	(255,885)
WES Operating [Member]
Consolidated statements of operations [Abstract]
General and administrative		35,242	28,101	74,300	48,661
Consolidated balance sheets [Abstract]
Accounts receivable, net		434,270		434,270		260,748
Consolidated statements of cash flows [Abstract]
Distributions to WES Operating unitholders	[2]			(433,718)	(546,629)
WES Operating [Member] | Related Parties [Member]
Consolidated statements of operations [Abstract]
General and administrative		11,168	$ 26,380	32,906	44,878
Consolidated balance sheets [Abstract]
Accounts receivable, net		$ 299,332		299,332		$ 113,581
Consolidated statements of cash flows [Abstract]
Distributions to WES Operating unitholders				$ (433,718)	$ (448,173)
[1]	See Note 6 .
[2]	See Note 6.

Related-Party Transactions - Ad

Related-Party Transactions - Additional Information (Details) - USD ($)		1 Months Ended	3 Months Ended				6 Months Ended
		May 31, 2008	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Related Party Transaction [Line Items]
Capital contribution for the above-market component of swap agreements with Anadarko	[1]					$ 7,407,000
WES Operating [Member]
Related Party Transaction [Line Items]
Cash contribution from related party				$ 20,000,000
Capital contribution for the above-market component of swap agreements with Anadarko	[2]					$ 7,407,000
Related Parties [Member]
Related Party Transaction [Line Items]
Operating lease, fixed-lease revenue			$ 44,000,000				$ 87,900,000
Operating lease, variable-lease revenue			17,200,000				32,800,000
Anadarko note receivable		$ 260,000,000
Anadarko note receivable - fixed annual rate		6.50%
Anadarko note receivable - interest receivable			2,800,000				2,800,000
Anadarko note receivable - allowance for expected credit loss			500,000				500,000
Related Parties [Member] | Commodity-Price Swap Agreements [Member]
Related Party Transaction [Line Items]
Net gains (losses) on commodity-price swap agreements					$ 0			$ (700,000)
Related Parties [Member] | Level-2 Inputs [Member] | Valuation, Market Approach [Member]
Related Party Transaction [Line Items]
Anadarko note receivable - fair value			241,500,000				241,500,000		$ 337,700,000
Related Parties [Member] | Incentive Plans [Member]
Related Party Transaction [Line Items]
Allocated equity-based compensation expense			$ 3,600,000		$ 4,000,000		$ 7,700,000	$ 5,800,000
Natural Gas [Member]
Related Party Transaction [Line Items]
Related-party throughput percentage			43.00%		37.00%		42.00%	37.00%
Crude Oil and NGLs Member]
Related Party Transaction [Line Items]
Related-party throughput percentage			88.00%		85.00%		88.00%	83.00%
Produced water [Member]
Related Party Transaction [Line Items]
Related-party throughput percentage			87.00%		80.00%		88.00%	82.00%
[1]	See Note 6 .
[2]	See Note 6 .

Equity Investments - Equity Inv

Equity Investments - Equity Investments Table (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Schedule of Equity Method Investments [Line Items]
Balance			$ 1,285,717
Equity income, net	$ 54,415	$ 63,598	115,762	$ 121,590
Contributions			16,064	77,333
Distributions			(124,156)	(115,483)
Distributions in excess of cumulative earnings			(13,340)	$ (17,052)
Balance	1,280,047		1,280,047
Fort Union [Member]
Schedule of Equity Method Investments [Line Items]
Balance			(610)
Equity income, net			(566)
Contributions			0
Distributions			0
Distributions in excess of cumulative earnings			0
Balance	(1,176)		(1,176)
White Cliffs [Member]
Schedule of Equity Method Investments [Line Items]
Balance			45,877
Equity income, net			4,368
Contributions			993
Distributions			(3,826)
Distributions in excess of cumulative earnings			(679)
Balance	46,733		46,733
Rendezvous [Member]
Schedule of Equity Method Investments [Line Items]
Balance			32,964
Equity income, net			187
Contributions			0
Distributions			(1,158)
Distributions in excess of cumulative earnings			(1,072)
Balance	30,921		30,921
Mont Belvieu JV [Member]
Schedule of Equity Method Investments [Line Items]
Balance			103,036
Equity income, net			13,734
Contributions			0
Distributions			(13,753)
Distributions in excess of cumulative earnings			(2,897)
Balance	100,120		100,120
Texas Express Gathering [Member]
Schedule of Equity Method Investments [Line Items]
Balance			18,199
Equity income, net			2,198
Contributions			0
Distributions			(2,209)
Distributions in excess of cumulative earnings			(1,356)
Balance	16,832		16,832
Texas Express Pipeline [Member]
Schedule of Equity Method Investments [Line Items]
Balance			203,556
Equity income, net			18,410
Contributions			0
Distributions			(21,588)
Distributions in excess of cumulative earnings			(592)
Balance	199,786		199,786
Front Range Pipeline [Member]
Schedule of Equity Method Investments [Line Items]
Balance			207,782
Equity income, net			19,909
Contributions			3,670
Distributions			(21,340)
Distributions in excess of cumulative earnings			(4,193)
Balance	205,828		205,828
Whitethorn LLC [Member]
Schedule of Equity Method Investments [Line Items]
Balance			161,665
Equity income, net			19,957
Contributions			278
Distributions			(20,811)
Distributions in excess of cumulative earnings			0
Balance	161,089		161,089
Cactus II [Member]
Schedule of Equity Method Investments [Line Items]
Balance			172,165
Equity income, net			10,955
Contributions			10,471
Distributions			(11,092)
Distributions in excess of cumulative earnings			0
Balance	182,499		182,499
Saddlehorn [Member]
Schedule of Equity Method Investments [Line Items]
Balance			112,855
Equity income, net			12,223
Contributions			0
Distributions			(13,644)
Distributions in excess of cumulative earnings			0
Balance	111,434		111,434
Panola [Member]
Schedule of Equity Method Investments [Line Items]
Balance			21,783
Equity income, net			984
Contributions			0
Distributions			(984)
Distributions in excess of cumulative earnings			(431)
Balance	21,352		21,352
Mi Vida [Member]
Schedule of Equity Method Investments [Line Items]
Balance			57,807
Equity income, net			5,178
Contributions			0
Distributions			(5,925)
Distributions in excess of cumulative earnings			(478)
Balance	56,582		56,582
Ranch Westex [Member]
Schedule of Equity Method Investments [Line Items]
Balance			46,678
Equity income, net			5,648
Contributions			0
Distributions			(5,249)
Distributions in excess of cumulative earnings			(705)
Balance	46,372		46,372
Red Bluff Express [Member]
Schedule of Equity Method Investments [Line Items]
Balance			101,960
Equity income, net			2,577
Contributions			652
Distributions			(2,577)
Distributions in excess of cumulative earnings			(937)
Balance	$ 101,675		$ 101,675

Equity Investments - Additional

Equity Investments - Additional Information (Details) $ in Millions	Jun. 30, 2020USD ($)
Saddlehorn [Member]
Schedule of Equity Method Investments [Line Items]
Equity investment difference between carrying and underlying value	$ (9.8)

Property, Plant, and Equipmen_2

Property, Plant, and Equipment - Historical Cost Table (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	$ 12,599,722	$ 12,355,671
Less accumulated depreciation	3,685,006	3,290,740
Net property, plant, and equipment	8,914,716	9,064,931
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	9,708	9,495
Gathering Systems – Pipelines [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	$ 5,203,293	5,092,004
Estimated useful life	30 years
Gathering Systems – Compressors [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	$ 2,033,154	1,929,377
Estimated useful life	15 years
Processing Complexes And Treating Facilities [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	$ 3,380,567	3,237,801
Estimated useful life	25 years
Transportation Pipeline And Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	$ 171,069	173,572
Transportation Pipeline And Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	6 years
Transportation Pipeline And Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	45 years
Produced-Water Disposal Systems [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	$ 810,275	754,774
Estimated useful life	20 years
Assets Under Construction [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	$ 289,418	486,584
Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	$ 702,238	$ 672,064
Other [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Other [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life	40 years

Property, Plant, and Equipmen_3

Property, Plant, and Equipment - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Long-lived asset impairments	$ 10,150	$ 797	$ 165,935	$ 1,187	$ 6,300
Wyoming and Utah Assets [Member]
Property, Plant and Equipment [Line Items]
Long-lived asset impairments			149,400
Wyoming and Utah Assets [Member] | Fair Value, Nonrecurring [Member] | Level-3 Inputs [Member] | Valuation, Income Approach [Member]
Property, Plant and Equipment [Line Items]
Estimated fair value	$ 112,200		112,200
DJ Basin Complex [Member]
Property, Plant and Equipment [Line Items]
Long-lived asset impairments			$ 16,500

Goodwill - Additional Informati

Goodwill - Additional Information (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Goodwill [Line Items]
Number of reporting units			2
Goodwill impairment	$ 0	$ 0	$ 441,017,000	$ 0
Goodwill	4,783,000		4,783,000		$ 445,800,000
Gathering and Processing Reporting Unit [Member]
Goodwill [Line Items]
Goodwill	0		0
Transportation Reporting Unit [Member]
Goodwill [Line Items]
Goodwill	$ 4,800,000		$ 4,800,000

Components of Working Capital -

Components of Working Capital - Accounts Receivable, Net Table (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Trade receivables, net	$ 457,405	$ 260,458
Other receivables, net	2,913	54
Total accounts receivable, net	460,318	260,512
WES Operating [Member]
Trade receivables, net	431,388	260,694
Other receivables, net	2,882	54
Total accounts receivable, net	$ 434,270	$ 260,748

Components of Working Capital_2

Components of Working Capital - Other Current Assets Table (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
NGLs inventory	$ 559	$ 906
Materials and supplies inventory	0	23,444
Imbalance receivables	7,985	4,690
Prepaid insurance	1,877	5,676
Contract assets	15,084	7,129
Other	13,602	93
Total other current assets	39,107	41,938
WES Operating [Member]
NGLs inventory	559	906
Materials and supplies inventory	0	23,444
Imbalance receivables	7,985	4,690
Prepaid insurance	495	3,652
Contract assets	15,084	7,129
Other	13,602	93
Total other current assets	$ 37,725	$ 39,914

Components of Working Capital_3

Components of Working Capital - Accrued Liabilities Table (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Accrued interest expense	$ 130,921	$ 72,064
Short-term asset retirement obligations	27,662	22,472
Short-term remediation and reclamation obligations	3,528	3,528
Income taxes payable	662	697
Contract liabilities	9,231	19,659
Other	45,221	31,373
Total accrued liabilities	217,225	149,793
WES Operating [Member]
Accrued interest expense	130,921	72,064
Short-term asset retirement obligations	27,662	22,472
Short-term remediation and reclamation obligations	3,528	3,528
Income taxes payable	662	697
Contract liabilities	9,231	19,659
Other	21,914	31,219
Total accrued liabilities	$ 193,918	$ 149,639

Debt and Interest Expense - Deb

Debt and Interest Expense - Debt Outstanding Table (Details) - USD ($)	Jun. 30, 2020	Jan. 13, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Total short-term debt, principal	$ 439,651,000		$ 7,873,000
Total short-term debt, carrying value	438,619,000		7,873,000
Long-term debt	7,544,396,000		7,951,565,000
Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Short-term debt, fair value	446,012,000		7,873,000
Long-Term Debt Obligations [Member]
Debt Instrument [Line Items]
Total long-term debt, principal	7,626,572,000		8,000,000,000
Long-term debt	7,544,396,000		7,951,565,000
Long-Term Debt Obligations [Member] | Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Long-term debt, fair value	7,025,756,000		7,849,818,000
WES Operating [Member]
Debt Instrument [Line Items]
Total short-term debt, carrying value	438,619,000		7,873,000
Long-term debt	7,544,396,000		7,951,565,000
WES Operating [Member] | Finance Lease Liability, Short Term [Member]
Debt Instrument [Line Items]
Finance leases - short-term debt	8,570,000		7,873,000
WES Operating [Member] | Finance Lease Liability, Short Term [Member] | Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Finance leases - short-term debt	8,570,000		7,873,000
WES Operating [Member] | RCF [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Principal	75,000,000		380,000,000
Long-term debt, carrying value	75,000,000		380,000,000
WES Operating [Member] | RCF [Member] | Revolving Credit Facility [Member] | Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Long-term debt, fair value	75,000,000		380,000,000
WES Operating [Member] | Term Loan Facility [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Principal	0		3,000,000,000
Long-term debt, carrying value	0		3,000,000,000
WES Operating [Member] | Term Loan Facility [Member] | Revolving Credit Facility [Member] | Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Long-term debt, fair value	0		3,000,000,000
WES Operating [Member] | Finance Lease Liability, Long Term [Member]
Debt Instrument [Line Items]
Finance leases - long-term debt	27,177,000		0
WES Operating [Member] | Finance Lease Liability, Long Term [Member] | Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Finance leases - long-term debt	$ 27,177,000		0
WES Operating [Member] | Senior Notes [Member] | 5.375% Senior Notes due 2021 [Member]
Debt Instrument [Line Items]
Senior note, interest rate	5.375%
Principal	$ 431,081,000		500,000,000
Short-term debt, carrying value	430,049,000
Long-term debt, carrying value			498,168,000
WES Operating [Member] | Senior Notes [Member] | 5.375% Senior Notes due 2021 [Member] | Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Short-term debt, fair value	$ 437,442,000
Long-term debt, fair value			515,042,000
WES Operating [Member] | Senior Notes [Member] | 4.000% Senior Notes due 2022 [Member]
Debt Instrument [Line Items]
Senior note, interest rate	4.00%
Principal	$ 584,417,000		670,000,000
Long-term debt, carrying value	583,937,000		669,322,000
WES Operating [Member] | Senior Notes [Member] | 4.000% Senior Notes due 2022 [Member] | Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Long-term debt, fair value	580,390,000		689,784,000
WES Operating [Member] | Senior Notes [Member] | Floating-Rate Senior Notes due 2023 [Member]
Debt Instrument [Line Items]
Principal	289,978,000		0
Long-term debt, carrying value	288,322,000		0
WES Operating [Member] | Senior Notes [Member] | Floating-Rate Senior Notes due 2023 [Member] | Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Long-term debt, fair value	$ 274,219,000		0
WES Operating [Member] | Senior Notes [Member] | 3.100% Senior Notes due 2025 [Member]
Debt Instrument [Line Items]
Senior note, interest rate	3.10%	3.10%
Principal	$ 1,000,000,000		0
Long-term debt, carrying value	992,109,000		0
WES Operating [Member] | Senior Notes [Member] | 3.100% Senior Notes due 2025 [Member] | Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Long-term debt, fair value	$ 954,941,000		0
WES Operating [Member] | Senior Notes [Member] | 3.950% Senior Notes due 2025 [Member]
Debt Instrument [Line Items]
Senior note, interest rate	3.95%
Principal	$ 500,000,000		500,000,000
Long-term debt, carrying value	494,343,000		493,830,000
WES Operating [Member] | Senior Notes [Member] | 3.950% Senior Notes due 2025 [Member] | Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Long-term debt, fair value	$ 470,309,000		504,968,000
WES Operating [Member] | Senior Notes [Member] | 4.650% Senior Notes due 2026 [Member]
Debt Instrument [Line Items]
Senior note, interest rate	4.65%
Principal	$ 500,000,000		500,000,000
Long-term debt, carrying value	496,450,000		496,197,000
WES Operating [Member] | Senior Notes [Member] | 4.650% Senior Notes due 2026 [Member] | Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Long-term debt, fair value	$ 481,202,000		513,393,000
WES Operating [Member] | Senior Notes [Member] | 4.500% Senior Notes due 2028 [Member]
Debt Instrument [Line Items]
Senior note, interest rate	4.50%
Principal	$ 400,000,000		400,000,000
Long-term debt, carrying value	395,362,000		395,113,000
WES Operating [Member] | Senior Notes [Member] | 4.500% Senior Notes due 2028 [Member] | Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Long-term debt, fair value	$ 379,742,000		390,920,000
WES Operating [Member] | Senior Notes [Member] | 4.750% Senior Notes due 2028 [Member]
Debt Instrument [Line Items]
Senior note, interest rate	4.75%
Principal	$ 400,000,000		400,000,000
Long-term debt, carrying value	396,370,000		396,190,000
WES Operating [Member] | Senior Notes [Member] | 4.750% Senior Notes due 2028 [Member] | Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Long-term debt, fair value	$ 384,618,000		400,962,000
WES Operating [Member] | Senior Notes [Member] | 4.050% Senior Notes due 2030 [Member]
Debt Instrument [Line Items]
Senior note, interest rate	4.05%	4.05%
Principal	$ 1,200,000,000		0
Long-term debt, carrying value	1,188,951,000		0
WES Operating [Member] | Senior Notes [Member] | 4.050% Senior Notes due 2030 [Member] | Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Long-term debt, fair value	$ 1,160,136,000		0
WES Operating [Member] | Senior Notes [Member] | 5.450% Senior Notes due 2044 [Member]
Debt Instrument [Line Items]
Senior note, interest rate	5.45%
Principal	$ 600,000,000		600,000,000
Long-term debt, carrying value	593,533,000		593,470,000
WES Operating [Member] | Senior Notes [Member] | 5.450% Senior Notes due 2044 [Member] | Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Long-term debt, fair value	$ 501,525,000		533,710,000
WES Operating [Member] | Senior Notes [Member] | 5.300% Senior Notes due 2048 [Member]
Debt Instrument [Line Items]
Senior note, interest rate	5.30%
Principal	$ 700,000,000		700,000,000
Long-term debt, carrying value	686,944,000		686,843,000
WES Operating [Member] | Senior Notes [Member] | 5.300% Senior Notes due 2048 [Member] | Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Long-term debt, fair value	$ 573,902,000		610,841,000
WES Operating [Member] | Senior Notes [Member] | 5.500% Senior Notes due 2048 [Member]
Debt Instrument [Line Items]
Senior note, interest rate	5.50%
Principal	$ 350,000,000		350,000,000
Long-term debt, carrying value	342,487,000		342,432,000
WES Operating [Member] | Senior Notes [Member] | 5.500% Senior Notes due 2048 [Member] | Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Long-term debt, fair value	$ 289,423,000		310,198,000
WES Operating [Member] | Senior Notes [Member] | 5.250% Senior Notes due 2050 [Member]
Debt Instrument [Line Items]
Senior note, interest rate	5.25%	5.25%
Principal	$ 1,000,000,000		0
Long-term debt, carrying value	983,411,000		0
WES Operating [Member] | Senior Notes [Member] | 5.250% Senior Notes due 2050 [Member] | Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Long-term debt, fair value	$ 873,172,000		$ 0

Debt and Interest Expense - D_2

Debt and Interest Expense - Debt Activity Table (Details) - USD ($)	Jan. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2020	Jan. 13, 2020
Changes in Debt Outstanding [Roll Forward]
Beginning balance			$ 7,959,438,000	$ 7,959,438,000
Other				(34,774,000)
Ending balance		$ 7,983,015,000		7,983,015,000
WES Operating [Member] | RCF [Member] | Revolving Credit Facility [Member]
Changes in Debt Outstanding [Roll Forward]
Facility borrowings				125,000,000
Repayments of facility borrowings				(430,000,000)
WES Operating [Member] | Floating-Rate Senior Notes due 2023 [Member] | Senior Notes [Member]
Changes in Debt Outstanding [Roll Forward]
Issuance of senior notes				300,000,000
Repayments of senior notes		$ (10,000,000)		(10,022,000)
WES Operating [Member] | 3.100% Senior Notes due 2025 [Member] | Senior Notes [Member]
Changes in Debt Outstanding [Roll Forward]
Issuance of senior notes				$ 1,000,000,000
Senior note, interest rate		3.10%		3.10%	3.10%
WES Operating [Member] | 4.050% Senior Notes due 2030 [Member] | Senior Notes [Member]
Changes in Debt Outstanding [Roll Forward]
Issuance of senior notes				$ 1,200,000,000
Senior note, interest rate		4.05%		4.05%	4.05%
WES Operating [Member] | 5.250% Senior Notes due 2050 [Member] | Senior Notes [Member]
Changes in Debt Outstanding [Roll Forward]
Issuance of senior notes				$ 1,000,000,000
Senior note, interest rate		5.25%		5.25%	5.25%
WES Operating [Member] | Finance Lease Liability [Member]
Changes in Debt Outstanding [Roll Forward]
Finance lease liabilities				$ 27,875,000
WES Operating [Member] | Term Loan Facility [Member] | Revolving Credit Facility [Member]
Changes in Debt Outstanding [Roll Forward]
Repayments of facility borrowings	$ (3,000,000,000)			(3,000,000,000)
WES Operating [Member] | 5.375% Senior Notes due 2021 [Member] | Senior Notes [Member]
Changes in Debt Outstanding [Roll Forward]
Repayments of senior notes		$ (7,500,000)	(61,400,000)	$ (68,919,000)
Senior note, interest rate		5.375%		5.375%
WES Operating [Member] | 4.000% Senior Notes due 2022 [Member] | Senior Notes [Member]
Changes in Debt Outstanding [Roll Forward]
Repayments of senior notes		$ (47,000,000)	$ (38,600,000)	$ (85,583,000)
Senior note, interest rate		4.00%		4.00%

Debt and Interest Expense - Int

Debt and Interest Expense - Interest Expense Table (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Debt Instrument [Line Items]
Interest expense	$ (94,654)	$ (79,472)	$ (183,240)	$ (145,348)
Third Parties [Member]
Debt Instrument [Line Items]
Long-term and short-term debt	(89,650)	(82,624)	(179,419)	(149,720)
Finance lease liabilities	(388)	0	(793)	0
Amortization of debt issuance costs and commitment fees	(3,462)	(3,170)	(6,589)	(6,322)
Capitalized interest	(1,154)	6,342	3,604	12,547
Interest expense	(94,654)	(79,452)	(183,197)	(143,495)
Related Parties [Member]
Debt Instrument [Line Items]
Finance lease liabilities	0	(20)	(43)	(20)
Interest expense	0	(20)	(43)	(1,853)
Related Parties [Member] | APCWH Note Payable [Member]
Debt Instrument [Line Items]
APCWH Note Payable	$ 0	$ 0	$ 0	$ (1,833)

Debt and Interest Expense - Add

Debt and Interest Expense - Additional Information (Details) - USD ($)	Jan. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Jan. 13, 2020	Jul. 01, 2019	Feb. 28, 2019	Dec. 31, 2018	Jun. 30, 2017
Debt Instrument [Line Items]
Gain (loss) on early extinguishment of debt			$ 1,395,000		$ 0		$ 8,740,000	$ 0
Cash paid to settle interest-rate swaps							12,763,000	0
Accrued liability on interest-rate swaps			217,225,000				217,225,000		$ 149,793,000
Gain (loss) on interest-rate swaps							0	(94,585,000)
WES Operating [Member]
Debt Instrument [Line Items]
Gain (loss) on early extinguishment of debt			1,395,000		0		8,740,000	0
Cash paid to settle interest-rate swaps							12,763,000	0
Accrued liability on interest-rate swaps			193,918,000				193,918,000		149,639,000
Gain (loss) on interest-rate swaps							0	(94,585,000)
WES Operating [Member] | Interest-Rate Swap [Member]
Debt Instrument [Line Items]
Cash paid to settle interest-rate swaps							12,800,000		107,700,000
Gain (loss) on interest-rate swaps					$ 59,000,000			$ 94,600,000
WES Operating [Member] | Not Designated as Hedging Instrument [Member] | Interest-Rate Swap [Member]
Debt Instrument [Line Items]
Interest-rate swap, notional amount						$ 375,000,000			1,125,000,000				$ 750,000,000
Accrued liability on interest-rate swaps									$ 25,600,000
WES Operating [Member] | Third Parties [Member]
Debt Instrument [Line Items]
Future lease payments			41,300,000				41,300,000
WES Operating [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Gain (loss) on early extinguishment of debt			$ 1,400,000				$ 11,000,000
WES Operating [Member] | Senior Notes [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Borrowing costs increase		$ 35,000,000
WES Operating [Member] | 3.100% Senior Notes due 2025 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Senior note, interest rate			3.10%				3.10%			3.10%
Senior note, offering percent										99.962%
Senior note, effective interest rate			3.287%				3.287%
WES Operating [Member] | 4.050% Senior Notes due 2030 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Senior note, interest rate			4.05%				4.05%			4.05%
Senior note, offering percent										99.90%
Senior note, effective interest rate			4.168%				4.168%
WES Operating [Member] | 5.250% Senior Notes due 2050 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Senior note, interest rate			5.25%				5.25%			5.25%
Senior note, offering percent										99.442%
Senior note, effective interest rate			5.362%				5.362%
WES Operating [Member] | Floating-Rate Senior Notes due 2023 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Senior note, effective interest rate			2.66%				2.66%
Repayments of senior notes			$ 10,000,000				$ 10,022,000
WES Operating [Member] | Floating-Rate Senior Notes due 2023 [Member] | Senior Notes [Member] | London Interbank Offered Rate (LIBOR) [Member] | Alternate Base Rate [Member]
Debt Instrument [Line Items]
Facility, applicable margin added							0.85%
WES Operating [Member] | Term Loan Facility [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility, repayment of borrowings	$ 3,000,000,000						$ 3,000,000,000
Gain (loss) on early extinguishment of debt				$ 2,300,000
Facility, maximum borrowing capacity											$ 3,000,000,000
Facility, interest rate at period end					3.78%			3.78%
WES Operating [Member] | 5.375% Senior Notes due 2021 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Senior note, interest rate			5.375%				5.375%
Repayments of senior notes			$ 7,500,000	61,400,000			$ 68,919,000
WES Operating [Member] | 4.000% Senior Notes due 2022 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Senior note, interest rate			4.00%				4.00%
Repayments of senior notes			$ 47,000,000	$ 38,600,000			$ 85,583,000
WES Operating [Member] | RCF [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility, repayment of borrowings							430,000,000
Facility, expandable maximum borrowing capacity												$ 2,500,000,000
Facility, maximum borrowing capacity			2,000,000,000				2,000,000,000					$ 2,000,000,000
Facility, outstanding borrowings			75,000,000				75,000,000
Facility, outstanding letters of credit			5,000,000				5,000,000
Facility, available borrowing capacity			$ 1,900,000,000				$ 1,900,000,000
Facility, interest rate at period end			1.66%		3.71%		1.66%	3.71%
Facility, fee rate			0.25%	0.20%			0.25%	0.20%
Facility, interest rate increase			0.20%
Facility, fee rate increase			0.05%
WES Operating [Member] | RCF [Member] | Revolving Credit Facility [Member] | Non-Extending Lender [Member]
Debt Instrument [Line Items]
Facility, borrowing capacity for non-extending lender			$ 100,000,000				$ 100,000,000
WES Operating [Member] | APCWH Note Payable [Member] | Maximum [Member]
Debt Instrument [Line Items]
APCWH Note Payable, maximum borrowing														$ 500,000,000
WES [Member] | WGP RCF [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility, repayment of borrowings						$ 28,000,000