Western Midstream Partners 10-Q 10 May 21 2021 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2021	May 05, 2021
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
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, Suite 2800
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		413,063,706
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	2021
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
WES Operating [Member]
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
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, Suite 2800
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	2021
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Revenues and Other
Revenues and other	[1]	$ 674,974	$ 774,313
Equity income, net – related parties		52,165	61,347
Operating expenses
Cost of product		88,969	103,270
Operation and maintenance		140,332	159,191
General and administrative		45,116	40,465
Property and other taxes		14,384	18,476
Depreciation and amortization		130,553	132,319
Long-lived asset and other impairments		14,866	155,785
Goodwill impairment		0	441,017
Total operating expenses	[2]	434,220	1,050,523
Gain (loss) on divestiture and other, net		(583)	(40)
Operating income (loss)		292,336	(214,903)
Interest income – Anadarko note receivable		0	4,225
Interest expense		(98,493)	(88,586)
Gain (loss) on early extinguishment of debt		(289)	7,345
Other income (expense), net		(1,207)	(1,761)
Income (loss) before income taxes		192,347	(293,680)
Income tax expense (benefit)		1,112	(4,280)
Net income (loss)		191,235	(289,400)
Net income (loss) attributable to noncontrolling interests		5,444	(32,873)
Net income (loss) attributable to Western Midstream Partners, LP		185,791	(256,527)
Limited partners' interest in net income (loss):
Net income (loss) attributable to Western Midstream Partners, LP		185,791	(256,527)
General partner interest in net (income) loss		(3,993)	5,131
Limited partners' interest in net income (loss)	[3]	$ 181,798	$ (251,396)
Limited Partner [Member]
Limited partners' interest in net income (loss):
Net income (loss) per common unit - basic and diluted	[3]	$ 0.44	$ (0.57)
Weighted-average common units outstanding - basic and diluted		413,104	443,971
Service Revenues - Fee Based [Member]
Revenues and Other
Revenues and other		$ 572,275	$ 701,396
Service Revenues - Product Based [Member]
Revenues and Other
Revenues and other		31,652	15,921
Product Sales [Member]
Revenues and Other
Revenues and other		70,805	56,649
Other [Member]
Revenues and Other
Revenues and other		$ 242	$ 347
[1]	Total revenues and other includes related - party amounts of $378.3 million and $482.4 million for the three months ended March 31, 2021 and 2020, respectively. See Note 6 .
[2]	Total operating expenses includes related - party amounts of $39.9 million and $132.6 million for the three months ended March 31, 2021 and 2020, respectively. See Note 6 .
[3]	See Note 5.

Consolidated Statements of Op_2

Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Total revenues and other	[1]	$ 674,974	$ 774,313
Total operating expenses	[2]	434,220	1,050,523
Related Parties [Member]
Total revenues and other		378,251	482,385
Total operating expenses		$ 39,862	$ 132,599
[1]	Total revenues and other includes related - party amounts of $378.3 million and $482.4 million for the three months ended March 31, 2021 and 2020, respectively. See Note 6 .
[2]	Total operating expenses includes related - party amounts of $39.9 million and $132.6 million for the three months ended March 31, 2021 and 2020, respectively. See Note 6 .

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands		Mar. 31, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents		$ 56,376	$ 444,922
Accounts receivable, net		480,705	452,880
Other current assets		74,079	45,262
Total current assets		611,160	943,064
Property, plant, and equipment
Cost		12,689,438	12,641,745
Less accumulated depreciation		4,049,900	3,931,800
Net property, plant, and equipment		8,639,538	8,709,945
Goodwill		4,783	4,783
Other intangible assets		768,492	776,409
Equity investments		1,215,875	1,224,813
Other assets	[1]	195,195	171,013
Total assets	[2]	11,435,043	11,830,027
Current liabilities
Accounts and imbalance payables		226,715	210,691
Short-term debt		7,752	438,870
Accrued ad valorem taxes		55,610	41,427
Accrued liabilities		200,185	269,947
Total current liabilities		490,262	960,935
Long-term liabilities
Long-term debt		7,416,001	7,415,832
Deferred income taxes		22,752	22,195
Asset retirement obligations		267,962	260,283
Other liabilities		295,946	275,570
Total long-term liabilities		8,002,661	7,973,880
Total liabilities	[3]	8,492,923	8,934,815
Equity and partners' capital
Common units (413,062,133 and 413,839,863 units issued and outstanding at March 31, 2021, and December 31, 2020, respectively)		2,821,455	2,778,339
General partner units (9,060,641 units issued and outstanding at March 31, 2021, and December 31, 2020)		(16,033)	(17,208)
Total partners' capital		2,805,422	2,761,131
Noncontrolling interests		136,698	134,081
Total equity and partners' capital		2,942,120	2,895,212
Total liabilities, equity, and partners' capital		$ 11,435,043	$ 11,830,027
Common units issued		413,062,133	413,839,863
Common units outstanding		413,062,133	413,839,863
General partner units issued		9,060,641	9,060,641
General partner units outstanding		9,060,641	9,060,641
[1]	Other assets includes $8.9 million and $4.2 million of NGLs line - fill inventory as of March 31, 2021, and December 31, 2020, respectively. Other assets also includes $68.5 million and $71.9 million of materials and supplies inventory as of March 31, 2021, and December 31, 2020, respectively.
[2]	Total assets includes related - party amounts of $1.5 billion and $1.6 billion as of March 31, 2021, and December 31, 2020, respectively, which includes related - party Accounts receivable, net of $253.6 million and $291.3 million as of March 31, 2021, and December 31, 2020, respectively. See Note 6 .
[3]	Total liabilities includes related - party amounts of $215.5 million and $164.7 million as of March 31, 2021, and December 31, 2020, respectively. See Note 6 .

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands		Mar. 31, 2021	Dec. 31, 2020
Materials and supplies inventory		$ 68,500	$ 71,900
Total assets	[1]	11,435,043	11,830,027
Accounts receivable, net		480,705	452,880
Total liabilities	[2]	8,492,923	8,934,815
Related Parties [Member]
Total assets		1,529,648	1,572,526
Accounts receivable, net		253,553	291,253
Total liabilities		215,549	164,655
Natural-Gas Liquids [Member]
NGLs line-fill inventory		$ 8,900	$ 4,200
[1]	Total assets includes related - party amounts of $1.5 billion and $1.6 billion as of March 31, 2021, and December 31, 2020, respectively, which includes related - party Accounts receivable, net of $253.6 million and $291.3 million as of March 31, 2021, and December 31, 2020, respectively. See Note 6 .
[2]	Total liabilities includes related - party amounts of $215.5 million and $164.7 million as of March 31, 2021, and December 31, 2020, respectively. See Note 6 .

Consolidated Statements of Equi

Consolidated Statements of Equity and Partners' Capital - USD ($) $ in Thousands		Total	Occidental [Member]	Chipeta [Member]	WES Operating [Member]	Common Units [Member]	Common Units [Member]Occidental [Member]	General Partner [Member]	Noncontrolling Interests [Member]	Noncontrolling Interests [Member]Chipeta [Member]	Noncontrolling Interests [Member]WES Operating [Member]
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 related parties			$ 4,105				$ 4,105
Equity-based compensation expense		1,129				1,129
Net contributions from (distributions to) related parties	[1]	20,489				489			20,000
Balance at Mar. 31, 2020		2,792,285				2,684,136		(24,990)	133,139
Balance at Dec. 31, 2020		2,895,212				2,778,339		(17,208)	134,081
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)		191,235				181,798		3,993	5,444
Distributions to noncontrolling interest owners				$ (276)	$ (2,551)					$ (276)	$ (2,551)
Distributions to Partnership unitholders		(131,265)				(128,447)		(2,818)
Unit repurchases	[2]	(16,241)				(16,241)
Contributions of equity-based compensation from related parties			$ 3,210				$ 3,210
Equity-based compensation expense		3,524				3,524
Net contributions from (distributions to) related parties		1,627				1,627
Other		(2,355)				(2,355)
Balance at Mar. 31, 2021		$ 2,942,120				$ 2,821,455		$ (16,033)	$ 136,698
[1]	See Services Agreement within Note 6 .
[2]	See Note 5 .

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities
Net income (loss)		$ 191,235	$ (289,400)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization		130,553	132,319
Long-lived asset and other impairments		14,866	155,785
Goodwill impairment		0	441,017
Non-cash equity-based compensation expense		6,734	5,234
Deferred income taxes		557	(2,168)
Accretion and amortization of long-term obligations, net		2,088	2,100
Equity income, net – related parties		(52,165)	(61,347)
Distributions from equity-investment earnings – related parties		49,048	60,868
(Gain) loss on divestiture and other, net		583	40
(Gain) loss on early extinguishment of debt		289	(7,345)
Other		11	2,287
Changes in assets and liabilities:
(Increase) decrease in accounts receivable, net		(30,182)	7,702
Increase (decrease) in accounts and imbalance payables and accrued liabilities, net		(16,467)	(28,924)
Change in other items, net		(35,600)	(24,857)
Net cash provided by operating activities		261,550	393,311
Cash flows from investing activities
Capital expenditures		(59,783)	(172,816)
Contributions to equity investments – related parties		(86)	(10,960)
Distributions from equity investments in excess of cumulative earnings – related parties		12,141	5,052
Decreases to materials and supplies inventory and other		3,256	0
Net cash used in investing activities		(46,472)	(178,724)
Cash flows from financing activities
Borrowings, net of debt issuance costs		100,000	3,586,173
Repayments of debt		(531,085)	(3,470,139)
Increase (decrease) in outstanding checks		(22,017)	(7,308)
Distributions to Partnership unitholders	[1]	(131,265)	(281,786)
Net contributions from (distributions to) related parties		1,627	20,489
Finance lease payments		(1,816)	(2,151)
Unit repurchases		16,241	0
Net cash provided by (used in) financing activities		(603,624)	(162,267)
Net increase (decrease) in cash and cash equivalents		(388,546)	52,320
Cash and cash equivalents at beginning of period		444,922	99,962
Cash and cash equivalents at end of period		56,376	152,282
Supplemental disclosures
Interest paid, net of capitalized interest		153,979	75,844
Taxes paid (reimbursements received)		932	(384)
Accrued capital expenditures		22,964	120,233
Chipeta [Member]
Cash flows from financing activities
Distributions to Chipeta noncontrolling interest owner		(276)	(1,738)
WES Operating [Member]
Cash flows from financing activities
Distributions to noncontrolling interest owners of WES Operating		(2,551)	(5,807)
Related Parties [Member]
Cash flows from investing activities
Acquisitions		(2,000)	0
Cash flows from financing activities
Distributions to Partnership unitholders		(66,642)	(150,609)
Finance lease payments		0	(202)
Related Parties [Member] | WES Operating [Member]
Cash flows from financing activities
Distributions to Partnership unitholders		$ (2,551)	$ (5,807)
[1]	See Note 6 .

Consolidated Statements of Op_3

Consolidated Statements of Operations - WES Operating - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Revenues and Other
Revenues and other	[1]	$ 674,974	$ 774,313
Equity income, net – related parties		52,165	61,347
Operating expenses
Cost of product		88,969	103,270
Operation and maintenance		140,332	159,191
General and administrative		45,116	40,465
Property and other taxes		14,384	18,476
Depreciation and amortization		130,553	132,319
Long-lived asset and other impairments		14,866	155,785
Goodwill impairment		0	441,017
Total operating expenses	[2]	434,220	1,050,523
Gain (loss) on divestiture and other, net		(583)	(40)
Operating income (loss)		292,336	(214,903)
Interest income – Anadarko note receivable		0	4,225
Interest expense		(98,493)	(88,586)
Gain (loss) on early extinguishment of debt		(289)	7,345
Other income (expense), net		(1,207)	(1,761)
Income (loss) before income taxes		192,347	(293,680)
Income tax expense (benefit)		1,112	(4,280)
Net income (loss)		191,235	(289,400)
Net income (loss) attributable to noncontrolling interest		5,444	(32,873)
Net income (loss) attributable to Western Midstream Operating, LP		185,791	(256,527)
Service Revenues - Fee Based [Member]
Revenues and Other
Revenues and other		572,275	701,396
Service Revenues - Product Based [Member]
Revenues and Other
Revenues and other		31,652	15,921
Product Sales [Member]
Revenues and Other
Revenues and other		70,805	56,649
Other [Member]
Revenues and Other
Revenues and other		242	347
WES Operating [Member]
Revenues and Other
Revenues and other	[3]	674,974	774,313
Equity income, net – related parties		52,165	61,347
Operating expenses
Cost of product		88,969	103,270
Operation and maintenance		140,332	159,191
General and administrative		44,230	39,058
Property and other taxes		14,384	18,476
Depreciation and amortization		130,553	132,319
Long-lived asset and other impairments		14,866	155,785
Goodwill impairment		0	441,017
Total operating expenses	[4]	433,334	1,049,116
Gain (loss) on divestiture and other, net		(583)	(40)
Operating income (loss)		293,222	(213,496)
Interest income – Anadarko note receivable		0	4,225
Interest expense		(98,493)	(88,586)
Gain (loss) on early extinguishment of debt		(289)	7,345
Other income (expense), net		(1,210)	(1,763)
Income (loss) before income taxes		193,230	(292,275)
Income tax expense (benefit)		1,112	(4,280)
Net income (loss)		192,118	(287,995)
Net income (loss) attributable to noncontrolling interest		1,633	(27,665)
Net income (loss) attributable to Western Midstream Operating, LP		190,485	(260,330)
WES Operating [Member] | Service Revenues - Fee Based [Member]
Revenues and Other
Revenues and other		572,275	701,396
WES Operating [Member] | Service Revenues - Product Based [Member]
Revenues and Other
Revenues and other		31,652	15,921
WES Operating [Member] | Product Sales [Member]
Revenues and Other
Revenues and other		70,805	56,649
WES Operating [Member] | Other [Member]
Revenues and Other
Revenues and other		$ 242	$ 347
[1]	Total revenues and other includes related - party amounts of $378.3 million and $482.4 million for the three months ended March 31, 2021 and 2020, respectively. See Note 6 .
[2]	Total operating expenses includes related - party amounts of $39.9 million and $132.6 million for the three months ended March 31, 2021 and 2020, respectively. See Note 6 .
[3]	Total revenues and other includes related - party amounts of $378.3 million and $482.4 million for the three months ended March 31, 2021 and 2020, respectively. See Note 6 .
[4]	Total operating expenses includes related - party amounts of $40.4 million and $132.5 million for the three months ended March 31, 2021 and 2020, respectively. See Note 6 .

Consolidated Statements of Op_4

Consolidated Statements of Operations - WES Operating (Parenthetical) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Total revenues and other	[1]	$ 674,974	$ 774,313
Total operating expenses	[2]	434,220	1,050,523
Related Parties [Member]
Total revenues and other		378,251	482,385
Total operating expenses		39,862	132,599
WES Operating [Member]
Total revenues and other	[3]	674,974	774,313
Total operating expenses	[4]	433,334	1,049,116
WES Operating [Member] | Related Parties [Member]
Total revenues and other		378,300	482,400
Total operating expenses		$ 40,400	$ 132,500
[1]	Total revenues and other includes related - party amounts of $378.3 million and $482.4 million for the three months ended March 31, 2021 and 2020, respectively. See Note 6 .
[2]	Total operating expenses includes related - party amounts of $39.9 million and $132.6 million for the three months ended March 31, 2021 and 2020, respectively. See Note 6 .
[3]	Total revenues and other includes related - party amounts of $378.3 million and $482.4 million for the three months ended March 31, 2021 and 2020, respectively. See Note 6 .
[4]	Total operating expenses includes related - party amounts of $40.4 million and $132.5 million for the three months ended March 31, 2021 and 2020, respectively. See Note 6 .

Consolidated Balance Sheets - W

Consolidated Balance Sheets - WES Operating - USD ($) $ in Thousands		Mar. 31, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents		$ 56,376	$ 444,922
Accounts receivable, net		480,705	452,880
Other current assets		74,079	45,262
Total current assets		611,160	943,064
Property, plant, and equipment
Cost		12,689,438	12,641,745
Less accumulated depreciation		4,049,900	3,931,800
Net property, plant, and equipment		8,639,538	8,709,945
Goodwill		4,783	4,783
Other intangible assets		768,492	776,409
Equity investments		1,215,875	1,224,813
Other assets	[1]	195,195	171,013
Total assets	[2]	11,435,043	11,830,027
Current liabilities
Accounts and imbalance payables		226,715	210,691
Short-term debt		7,752	438,870
Accrued ad valorem taxes		55,610	41,427
Accrued liabilities		200,185	269,947
Total current liabilities		490,262	960,935
Long-term liabilities
Long-term debt		7,416,001	7,415,832
Deferred income taxes		22,752	22,195
Asset retirement obligations		267,962	260,283
Other liabilities		295,946	275,570
Total long-term liabilities		8,002,661	7,973,880
Total liabilities	[3]	8,492,923	8,934,815
Equity and partners' capital
Common units (318,675,578 units issued and outstanding at March 31, 2021, and December 31, 2020)		2,821,455	2,778,339
Total partners' capital		2,805,422	2,761,131
Noncontrolling interest		136,698	134,081
Total equity and partners' capital		2,942,120	2,895,212
Total liabilities, equity, and partners' capital		$ 11,435,043	$ 11,830,027
Common units issued		413,062,133	413,839,863
Common units outstanding		413,062,133	413,839,863
Related Parties [Member]
Current assets
Accounts receivable, net		$ 253,553	$ 291,253
Other current assets		14,096	5,493
Property, plant, and equipment
Other assets		46,124	50,967
Total assets		1,529,648	1,572,526
Current liabilities
Accounts and imbalance payables		8,929	6,664
Accrued liabilities		52,779	19,195
Long-term liabilities
Other liabilities		153,841	138,796
Total liabilities		215,549	164,655
WES Operating [Member]
Current assets
Cash and cash equivalents		52,504	418,537
Accounts receivable, net		458,089	407,549
Other current assets		72,488	43,244
Total current assets		583,081	869,330
Property, plant, and equipment
Cost		12,689,438	12,641,745
Less accumulated depreciation		4,049,900	3,931,800
Net property, plant, and equipment		8,639,538	8,709,945
Goodwill		4,783	4,783
Other intangible assets		768,492	776,409
Equity investments		1,215,875	1,224,813
Other assets	[4]	195,195	171,013
Total assets	[5]	11,406,964	11,756,293
Current liabilities
Accounts and imbalance payables		225,992	210,532
Short-term debt		7,752	438,870
Accrued ad valorem taxes		55,610	41,427
Accrued liabilities		174,163	230,833
Total current liabilities		463,517	921,662
Long-term liabilities
Long-term debt		7,416,001	7,415,832
Deferred income taxes		22,752	22,195
Asset retirement obligations		267,962	260,283
Other liabilities		295,946	275,570
Total long-term liabilities		8,002,661	7,973,880
Total liabilities	[6]	8,466,178	8,895,542
Equity and partners' capital
Common units (318,675,578 units issued and outstanding at March 31, 2021, and December 31, 2020)		2,909,877	2,831,199
Total partners' capital		2,909,877	2,831,199
Noncontrolling interest		30,909	29,552
Total equity and partners' capital		2,940,786	2,860,751
Total liabilities, equity, and partners' capital		$ 11,406,964	$ 11,756,293
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		$ 231,286	$ 246,083
Property, plant, and equipment
Total assets		1,500,000	1,500,000
Long-term liabilities
Total liabilities		$ 215,200	$ 164,300
[1]	Other assets includes $8.9 million and $4.2 million of NGLs line - fill inventory as of March 31, 2021, and December 31, 2020, respectively. Other assets also includes $68.5 million and $71.9 million of materials and supplies inventory as of March 31, 2021, and December 31, 2020, respectively.
[2]	Total assets includes related - party amounts of $1.5 billion and $1.6 billion as of March 31, 2021, and December 31, 2020, respectively, which includes related - party Accounts receivable, net of $253.6 million and $291.3 million as of March 31, 2021, and December 31, 2020, respectively. See Note 6 .
[3]	Total liabilities includes related - party amounts of $215.5 million and $164.7 million as of March 31, 2021, and December 31, 2020, respectively. See Note 6 .
[4]	Other assets includes $8.9 million and $4.2 million of NGLs line - fill inventory as of March 31, 2021, and December 31, 2020, respectively. Other assets also includes $68.5 million and $71.9 million of materials and supplies inventory as of March 31, 2021, and December 31, 2020, respectively.
[5]	Total assets includes related - party amounts of $1.5 billion as of March 31, 2021, and December 31, 2020, which includes related - party Accounts receivable, net of $231.3 million and $246.1 million as of March 31, 2021, and December 31, 2020, respectively. See Note 6 .
[6]	Total liabilities includes related - party amounts of $215.2 million and $164.3 million as of March 31, 2021, and December 31, 2020, respectively. See Note 6 .

Consolidated Balance Sheets -_2

Consolidated Balance Sheets - WES Operating (Parenthetical) - USD ($) $ in Thousands		Mar. 31, 2021	Dec. 31, 2020
Materials and supplies inventory		$ 68,500	$ 71,900
Total assets	[1]	11,435,043	11,830,027
Accounts receivable, net		480,705	452,880
Total liabilities	[2]	8,492,923	8,934,815
Related Parties [Member]
Total assets		1,529,648	1,572,526
Accounts receivable, net		253,553	291,253
Total liabilities		215,549	164,655
Natural-Gas Liquids [Member]
NGLs line-fill inventory		8,900	4,200
WES Operating [Member]
Materials and supplies inventory		68,500	71,900
Total assets	[3]	11,406,964	11,756,293
Accounts receivable, net		458,089	407,549
Total liabilities	[4]	8,466,178	8,895,542
WES Operating [Member] | Related Parties [Member]
Total assets		1,500,000	1,500,000
Accounts receivable, net		231,286	246,083
Total liabilities		215,200	164,300
WES Operating [Member] | Natural-Gas Liquids [Member]
NGLs line-fill inventory		$ 8,900	$ 4,200
[1]	Total assets includes related - party amounts of $1.5 billion and $1.6 billion as of March 31, 2021, and December 31, 2020, respectively, which includes related - party Accounts receivable, net of $253.6 million and $291.3 million as of March 31, 2021, and December 31, 2020, respectively. See Note 6 .
[2]	Total liabilities includes related - party amounts of $215.5 million and $164.7 million as of March 31, 2021, and December 31, 2020, respectively. See Note 6 .
[3]	Total assets includes related - party amounts of $1.5 billion as of March 31, 2021, and December 31, 2020, which includes related - party Accounts receivable, net of $231.3 million and $246.1 million as of March 31, 2021, and December 31, 2020, respectively. See Note 6 .
[4]	Total liabilities includes related - party amounts of $215.2 million and $164.3 million as of March 31, 2021, and December 31, 2020, respectively. See Note 6 .

Consolidated Statements of Eq_2

Consolidated Statements of Equity and Partners' Capital - WES Operating - USD ($) $ in Thousands	Total		Occidental [Member]	Chipeta [Member]	Common Units [Member]		Common Units [Member]Occidental [Member]	Noncontrolling Interest [Member]		Noncontrolling Interest [Member]Chipeta [Member]	WES Operating [Member]		WES Operating [Member]Occidental [Member]	WES Operating [Member]WES [Member]	WES Operating [Member]Chipeta [Member]	WES Operating [Member]Common Units [Member]		WES Operating [Member]Common Units [Member]Occidental [Member]	WES Operating [Member]Common Units [Member]WES [Member]	WES Operating [Member]Noncontrolling Interest [Member]	WES Operating [Member]Noncontrolling Interest [Member]Chipeta [Member]
Balance at Dec. 31, 2019	$ 3,345,293				$ 3,209,947			$ 149,570			$ 3,341,819					$ 3,286,620				$ 55,199
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)	(289,400)				(251,396)			(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)						(290,314)					(290,314)
Contributions of equity-based compensation from related parties			$ 4,105				$ 4,105						$ 4,105					$ 4,105
Acquisitions from related parties	0				(3,987)			3,987			0					(3,987)				3,987
Net contributions from (distributions to) related parties	20,489	[1]			489	[1]		20,000	[1]		20,489	[2]				20,489	[2]
Balance at Mar. 31, 2020	2,792,285				2,684,136			133,139			2,786,366					2,756,583				29,783
Balance at Dec. 31, 2020	2,895,212				2,778,339			134,081			2,860,751					2,831,199				29,552
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)	191,235				181,798			5,444			192,118					190,485				1,633
Distributions to noncontrolling interest owners				$ (276)						$ (276)					$ (276)						$ (276)
Distributions to WES Operating unitholders	(131,265)				(128,447)						(127,470)					(127,470)
Contributions of equity-based compensation from related parties			$ 3,210				$ 3,210						$ 3,210	$ 10,826				$ 3,210	$ 10,826
Net contributions from (distributions to) related parties	1,627				1,627						1,627					1,627
Balance at Mar. 31, 2021	$ 2,942,120				$ 2,821,455			$ 136,698			$ 2,940,786					$ 2,909,877				$ 30,909
[1]	See Services Agreement within Note 6 .
[2]	See Services Agreement within Note 6 .

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows - WES Operating - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities
Net income (loss)		$ 191,235	$ (289,400)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization		130,553	132,319
Long-lived asset and other impairments		14,866	155,785
Goodwill impairment		0	441,017
Non-cash equity-based compensation expense		6,734	5,234
Deferred income taxes		557	(2,168)
Accretion and amortization of long-term obligations, net		2,088	2,100
Equity income, net – related parties		(52,165)	(61,347)
Distributions from equity-investment earnings – related parties		49,048	60,868
(Gain) loss on divestiture and other, net		583	40
(Gain) loss on early extinguishment of debt		289	(7,345)
Other		11	2,287
Changes in assets and liabilities:
(Increase) decrease in accounts receivable, net		(30,182)	7,702
Increase (decrease) in accounts and imbalance payables and accrued liabilities, net		(16,467)	(28,924)
Change in other items, net		(35,600)	(24,857)
Net cash provided by operating activities		261,550	393,311
Cash flows from investing activities
Capital expenditures		(59,783)	(172,816)
Contributions to equity investments – related parties		(86)	(10,960)
Distributions from equity investments in excess of cumulative earnings – related parties		12,141	5,052
Decreases to materials and supplies inventory and other		3,256	0
Net cash used in investing activities		(46,472)	(178,724)
Cash flows from financing activities
Borrowings, net of debt issuance costs		100,000	3,586,173
Repayments of debt		(531,085)	(3,470,139)
Increase (decrease) in outstanding checks		(22,017)	(7,308)
Distributions to WES Operating unitholders	[1]	(131,265)	(281,786)
Net contributions from (distributions to) related parties		1,627	20,489
Finance lease payments		(1,816)	(2,151)
Net cash provided by (used in) financing activities		(603,624)	(162,267)
Net increase (decrease) in cash and cash equivalents		(388,546)	52,320
Cash and cash equivalents at beginning of period		444,922	99,962
Cash and cash equivalents at end of period		56,376	152,282
Supplemental disclosures
Interest paid, net of capitalized interest		153,979	75,844
Taxes paid (reimbursements received)		932	(384)
Accrued capital expenditures		22,964	120,233
Chipeta [Member]
Cash flows from financing activities
Distributions to Chipeta noncontrolling interest owner		(276)	(1,738)
Related Parties [Member]
Cash flows from investing activities
Acquisitions		(2,000)	0
Cash flows from financing activities
Distributions to WES Operating unitholders		(66,642)	(150,609)
Finance lease payments		0	(202)
WES Operating [Member]
Cash flows from operating activities
Net income (loss)		192,118	(287,995)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization		130,553	132,319
Long-lived asset and other impairments		14,866	155,785
Goodwill impairment		0	441,017
Non-cash equity-based compensation expense		14,036	4,105
Deferred income taxes		557	(2,168)
Accretion and amortization of long-term obligations, net		2,088	2,100
Equity income, net – related parties		(52,165)	(61,347)
Distributions from equity-investment earnings – related parties		49,048	60,868
(Gain) loss on divestiture and other, net		583	40
(Gain) loss on early extinguishment of debt		289	(7,345)
Other		11	2,287
Changes in assets and liabilities:
(Increase) decrease in accounts receivable, net		(50,540)	15,334
Increase (decrease) in accounts and imbalance payables and accrued liabilities, net		(3,748)	(35,474)
Change in other items, net		(36,028)	(25,176)
Net cash provided by operating activities		261,668	394,350
Cash flows from investing activities
Capital expenditures		(59,783)	(172,816)
Contributions to equity investments – related parties		(86)	(10,960)
Distributions from equity investments in excess of cumulative earnings – related parties		12,141	5,052
Decreases to materials and supplies inventory and other		3,256	0
Net cash used in investing activities		(46,472)	(178,724)
Cash flows from financing activities
Borrowings, net of debt issuance costs		100,000	3,586,173
Repayments of debt		(531,085)	(3,470,139)
Increase (decrease) in outstanding checks		(22,209)	(7,308)
Distributions to WES Operating unitholders	[2]	(127,470)	(290,314)
Net contributions from (distributions to) related parties		1,627	20,489
Finance lease payments		(1,816)	(2,151)
Net cash provided by (used in) financing activities		(581,229)	(164,988)
Net increase (decrease) in cash and cash equivalents		(366,033)	50,638
Cash and cash equivalents at beginning of period		418,537	98,122
Cash and cash equivalents at end of period		52,504	148,760
Supplemental disclosures
Interest paid, net of capitalized interest		153,979	75,844
Taxes paid (reimbursements received)		932	(384)
Accrued capital expenditures		22,964	120,233
WES Operating [Member] | Chipeta [Member]
Cash flows from financing activities
Distributions to Chipeta noncontrolling interest owner		(276)	(1,738)
WES Operating [Member] | Related Parties [Member]
Cash flows from investing activities
Acquisitions		(2,000)	0
Cash flows from financing activities
Distributions to WES Operating unitholders		$ (127,470)	$ (290,314)
[1]	See Note 6 .
[2]	See Note 6.

Description of Business and Bas

Description of Business and Basis of Presentation	3 Months Ended
	Mar. 31, 2021
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 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. 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. “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. “Related parties” refers to Occidental (see Note 6 ) and the Partnership’s investments accounted for under the equity method of accounting (see Note 7 ). 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 March 31, 2021, the Partnership’s assets and investments consisted of the following: Wholly Operated Non-Operated Equity Gathering systems (1) 17 2 3 1 Treating facilities 39 3 — — Natural - gas processing plants/trains 25 3 — 5 NGLs pipelines 2 — — 5 Natural - gas pipelines 5 — — 1 Crude - oil pipelines 3 1 — 4 _________________________________________________________________________________________ (1) Includes the DBM water systems. These assets and investments are located in Texas, New Mexico, the Rocky Mountains (Colorado, Utah, and Wyoming), and North - central Pennsylvania. 1. DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION Basis of presentation. The consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) and include the accounts of the Partnership and entities in which it holds a controlling financial interest, including WES Operating, WES Operating GP, proportionately consolidated interests, and equity investments (see table below). 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 JV LLC (“Mi Vida”) 50.00 % Ranch Westex JV LLC (“Ranch Westex”) 50.00 % Front Range Pipeline LLC (“FRP”) 33.33 % Red Bluff Express Pipeline, LLC (“Red Bluff Express”) 30.00 % Enterprise EF78 LLC (“Mont Belvieu JV”) 25.00 % Rendezvous Gas Services, LLC (“Rendezvous”) 22.00 % Texas Express Pipeline LLC (“TEP”) 20.00 % Texas Express Gathering LLC (“TEG”) 20.00 % Whitethorn Pipeline Company LLC (“Whitethorn LLC”) 20.00 % Saddlehorn Pipeline Company, LLC (“Saddlehorn”) 20.00 % Cactus II Pipeline LLC (“Cactus II”) 15.00 % Panola Pipeline Company, LLC (“Panola”) 15.00 % White Cliffs Pipeline, LLC (“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. Certain information and note disclosures commonly included in annual financial statements have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Accordingly, the accompanying consolidated financial statements and notes should be read in conjunction with the Partnership’s 2020 Form 10 - K, as filed with the SEC on February 26, 2021. Management believes that the disclosures made are adequate to make the information not misleading. 1. DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION 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), (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, and (iv) the inclusion of the impact of Partnership equity balances and Partnership distributions. 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 March 31, 2021 (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. Noncontrolling interests. 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. WES Operating’s noncontrolling interest in the consolidated financial statements consists of the 25% third - party interest in Chipeta. See Note 5. 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. During the three months ended March 31, 2021, the Partnership issued 338,078 common units under the Western Gas Equity Partners, LP 2012 Long - Term Incentive Plan (“WES LTIP”). Compensation expense for the WES LTIP was $3.5 million and $1.1 million for the three months ended March 31, 2021 and 2020, respectively. On March 22, 2021, the Board of Directors approved the Western Midstream Partners, LP 2021 Long - Term Incentive Plan, which authorized the issuance of up to 9.5 million of the Partnership’s common units. This plan provides for the grant of unit options, unit appreciation rights, restricted units, phantom units, other unit - based awards, cash awards, and a unit award or a substitute award to employees and directors of the Partnership and its general partner. Affiliates of Occidental who held a majority of the Partnership’s outstanding common units as of March 22, 2021, approved the 2021 Long - Term Incentive Plan via written consent. On April 7, 2021, the Partnership mailed an information statement on Schedule 14C to its unitholders of record as of March 22, 2021. The 2021 Long - Term Incentive Plan became effective on April 27, 2021, which is 20 calendar days after the Partnership mailed out the information statement. 1. DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION 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 $6.9 million and $0.4 million for the three months ended March 31, 2021 and 2020, respectively.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	3 Months Ended
	Mar. 31, 2021
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 thousands 2021 2020 Revenue from customers Service revenues – fee based $ 529,413 $ 641,921 Service revenues – product based 31,652 15,921 Product sales 70,805 56,649 Total revenue from customers 631,870 714,491 Revenue from other than customers Lease revenue (1) 42,862 59,475 Other 242 347 Total revenues and other $ 674,974 $ 774,313 _________________________________________________________________________________________ (1) Includes fixed - and variable - lease revenue from an operating and maintenance agreement entered into with Occidental. See Operating lease within Note 6. Certain of the Partnership’s midstream services contracts have minimum - volume commitment demand fees and fees that require periodic rate redeterminations based on the related facility cost - of - service rate provisions. During the year ended December 31, 2020, and the quarter ended March 31, 2021, the Partnership constrained revenue on certain cost-of-service agreements based on the status of commercial negotiations relating to a legal dispute with one of our contract counterparties. Future revenue reversals could occur to the extent the outcome of the legal proceedings and commercial negotiations differ from our current assumptions. 2. REVENUE FROM CONTRACTS WITH CUSTOMERS Contract balances. Receivables from customers, which are included in Accounts receivable, net on the consolidated balance sheets were $469.3 million and $428.2 million as of March 31, 2021, and December 31, 2020, respectively. Contract assets primarily relate to (i) revenue accrued but not yet billed under cost - of - service contracts with fixed and variable fees and (ii) accrued deficiency fees the Partnership expects to charge customers once the related performance periods are completed. The following table summarizes activity related to contract assets from contracts with customers: thousands Contract assets balance at December 31, 2020 $ 56,344 Additional estimated revenues recognized 4,571 Contract assets balance at March 31, 2021 $ 60,915 Contract assets at March 31, 2021 Other current assets $ 14,745 Other assets 46,170 Total contract assets from contracts with customers $ 60,915 Contract liabilities primarily relate to (i) aid - in - construction payments received from customers that must be recognized 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) 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. The following table summarizes activity related to contract liabilities from contracts with customers: thousands Contract liabilities balance at December 31, 2020 $ 266,937 Cash received or receivable, excluding revenues recognized during the period 15,260 Revenues recognized that were included in the contract liability balance at the beginning of the period (2,067) Contract liabilities balance at March 31, 2021 $ 280,130 Contract liabilities at March 31, 2021 Accrued liabilities $ 19,250 Other liabilities 260,880 Total contract liabilities from contracts with customers $ 280,130 2. REVENUE FROM CONTRACTS WITH CUSTOMERS Transaction price allocated to remaining performance obligations. Revenues expected to be recognized from certain performance obligations that are unsatisfied (or partially unsatisfied) as of March 31, 2021, are presented in the following table. The Partnership applies the optional exemptions in Revenue from Contracts with Customers (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 2021 $ 618,392 2022 1,055,916 2023 1,000,434 2024 971,137 2025 888,850 Thereafter 2,715,378 Total $ 7,250,107

Acquisitions and Divestitures

Acquisitions and Divestitures	3 Months Ended
	Mar. 31, 2021
Property, Plant and Equipment [Abstract]
Acquisitions and Divestitures	3. ACQUISITIONS AND DIVESTITURES Fort Union and Bison facilities. In October 2020, the Partnership (i) sold its 14.81% interest in Fort Union Gas Gathering, LLC (“Fort Union”), which was accounted for under the equity method of accounting, and (ii) entered into an option agreement to sell the Bison treating facility, located in Northeast Wyoming, to a third party, initially exercisable during the first quarter of 2021 and subsequently extended to May 9, 2021. The Partnership received combined proceeds of $27.0 million, resulting in a net gain on sale of $21.0 million related to the Fort Union interest that was recorded in the fourth quarter of 2020 as Gain (loss) on divestiture and other, net in the consolidated statements of operations. During the second quarter of 2021, the third party exercised its option to purchase the Bison treating facility and it satisfied the held - for - sale criteria. The sale is expected to close in the second quarter of 2021.

Partnership Distributions

Partnership Distributions	3 Months Ended
	Mar. 31, 2021
Distributions Made to Members or Limited Partners [Abstract]
Partnership Distributions	4. PARTNERSHIP DISTRIBUTIONS Partnership distributions. Under its partnership agreement, the Partnership distributes all of its available cash (beyond proper reserves 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 2020 March 31 $ 0.31100 $ 140,893 May 2020 June 30 0.31100 140,900 August 2020 September 30 0.31100 132,255 November 2020 December 31 0.31100 131,265 February 2021 2021 March 31 (1) $ 0.31500 $ 132,969 May 2021 _________________________________________________________________________________________ (1) The Board of Directors declared a cash distribution to the Partnership’s unitholders for the first quarter of 2021 of $0.31500 per unit, or $133.0 million in aggregate. The cash distribution is payable on May 14, 2021 to unitholders of record at the close of business on April 30, 2021, including the general partner units. Available cash. The amount of available cash (beyond proper reserves as defined in our 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 and 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. WES Operating makes quarterly cash distributions to the Partnership and WGR Asset Holding Company LLC (“WGRAH”), a subsidiary of Occidental, in proportion to their share of limited partner interests in WES Operating. See Note 5 . WES Operating made the following cash distributions to its limited partners for the periods presented: thousands Quarters Ended Total Quarterly 2020 March 31 $ 143,404 June 30 143,404 September 30 143,404 December 31 127,470 2021 March 31 $ 137,030

Equity and Partners' Capital

Equity and Partners' Capital	3 Months Ended
	Mar. 31, 2021
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 March 31, 2021, Occidental held 202,781,578 common units, representing a 48.0% 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 2.2% general partner interest in the Partnership. The public held 210,280,555 common units, representing a 49.8% limited partner interest in the Partnership. In March 2021, an affiliate of Occidental sold 11,500,000 of the Partnership’s common units it held to the public through an underwritten offering, including 1,500,000 common units pursuant to the full exercise of the underwriters’ over - allotment option. The Partnership did not receive any proceeds from the public offering. On September 11, 2020, the Partnership assigned its 98% interest in the 30 - year $260.0 million note established in May 2008 between WES Operating and Anadarko (the “Anadarko note receivable”) to Anadarko, which Anadarko canceled and retired immediately upon receipt, in exchange for which Occidental caused certain of its subsidiaries to transfer an aggregate of 27,855,398 common units representing limited partner interests in the Partnership to the Partnership. The units were canceled by the Partnership immediately upon receipt. See Note 6. Partnership equity repurchases. In November 2020, the Board of Directors authorized the Partnership to buy back up to $250.0 million of the Partnership’s common units through December 31, 2021 (the “Purchase Program”). The common units may be purchased from time to time in the open market at prevailing market prices or in privately negotiated transactions. During the quarter ended March 31, 2021, the Partnership repurchased 1,115,808 common units on the open market for an aggregate purchase price of $16.2 million. The units were canceled by the Partnership immediately upon receipt. As of March 31, 2021, the Partnership had an authorized amount of $201.2 million remaining under the Purchase Program. Holdings of WES Operating equity. As of March 31, 2021, (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 ). Partnership’s net income (loss) per common unit. 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 (beyond proper reserves 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. WES Operating’s net income (loss) per common unit. Net income (loss) per common unit for WES Operating is not calculated because it has no publicly traded units.

Related-Party Transactions

Related-Party Transactions	3 Months Ended
	Mar. 31, 2021
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 thousands 2021 2020 Revenues and other Service revenues – fee based $ 367,475 $ 447,783 Service revenues – product based 4,505 2,978 Product sales 6,271 31,624 Total revenues and other 378,251 482,385 Equity income, net – related parties (1) 52,165 61,347 Operating expenses Cost of product 17,647 77,903 Operation and maintenance 18,122 32,841 General and administrative (2) 4,093 21,855 Total operating expenses 39,862 132,599 Interest income – Anadarko note receivable — 4,225 Interest expense — (43) _________________________________________________________________________________________ (1) See Note 7 . (2) Includes (i) amounts charged by Occidental pursuant to the shared services agreement (see Services Agreement within this Note 6 ) and (ii) equity - based compensation expense allocated to the Partnership by Occidental, which is not reimbursed to Occidental and is reflected as a contribution to partners’ capital in the consolidated statements of equity and partners’ capital (see Incentive Plans within this Note 6 ). 6. RELATED-PARTY TRANSACTIONS Consolidated balance sheets thousands March 31, December 31, Assets Accounts receivable, net $ 253,553 $ 291,253 Other current assets 14,096 5,493 Equity investments (1) 1,215,875 1,224,813 Other assets (2) 46,124 50,967 Total assets 1,529,648 1,572,526 Liabilities Accounts and imbalance payables 8,929 6,664 Accrued liabilities 52,779 19,195 Other liabilities 153,841 138,796 Total liabilities 215,549 164,655 _________________________________________________________________________________________ (1) See Note 7 . (2) For the three months ended March 31, 2021, includes the addition of a $30.0 million right - of - use (“ROU”) asset recognized in connection with related - party operating leases (see Operating lease within this Note 6) . Consolidated statements of cash flows Three Months Ended thousands 2021 2020 Distributions from equity - investment earnings – related parties $ 49,048 $ 60,868 Acquisitions from related parties (2,000) — Contributions to equity investments – related parties (86) (10,960) Distributions from equity investments in excess of cumulative earnings – related parties 12,141 5,052 Distributions to Partnership unitholders (1) (66,642) (150,609) Distributions to WES Operating unitholders (2) (2,551) (5,807) Net contributions from (distributions to) related parties 1,627 20,489 Finance lease payments — (202) _________________________________________________________________________________________ (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 a certain subsidiary of Occidental pursuant to WES Operating’s partnership agreement (see Note 4 and Note 5 ). 6. RELATED-PARTY TRANSACTIONS 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 thousands 2021 2020 General and administrative (1) $ 4,587 $ 21,738 _________________________________________________________________________________________ (1) Includes (i) amounts charged by Occidental pursuant to the shared services agreement (see Services Agreement within this Note 6 ) and (ii) equity - based compensation expense allocated to WES Operating by Occidental, which is not reimbursed to Occidental and is reflected as a contribution to partners’ capital in the consolidated statements of equity and partners’ capital (see Incentive Plans within this Note 6 ). Consolidated balance sheets thousands March 31, December 31, Accounts receivable, net $ 231,286 $ 246,083 Consolidated statements of cash flows Three Months Ended thousands 2021 2020 Distributions to WES Operating unitholders (1) $ (127,470) $ (290,314) _________________________________________________________________________________________ (1) Represents distributions paid to the Partnership and a certain subsidiary of Occidental pursuant to WES Operating’s partnership agreement (see Note 4 and Note 5 ). 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. While Occidental is the contracting counterparty of the Partnership, these arrangements with Occidental include not just Occidental - produced volumes, but also, in some instances, the volumes of other working - interest owners of Occidental who rely on the Partnership’s facilities and infrastructure to bring their volumes to market. Natural - gas throughput (excluding equity - investment throughput) attributable to production owned or controlled by Occidental was 35% and 42% for the three months ended March 31, 2021 and 2020, respectively. Crude - oil and NGLs throughput (excluding equity - investment throughput) attributable to production owned or controlled by Occidental was 88% and 89% for the three months ended March 31, 2021 and 2020, respectively. Produced - water throughput attributable to production owned or controlled by Occidental was 86% and 89% for the three months ended March 31, 2021 and 2020, respectively. The Partnership is currently involved in a dispute with Occidental regarding the calculation of the cost - of - service rates under an oil - gathering contract related to the Partnership’s DJ Basin oil - gathering system. If such dispute is resolved in a manner adverse to the Partnership, such resolution could have a negative impact on our financial condition and results of operations, including a reduction in rates and a non - cash charge to earnings. 6. RELATED-PARTY TRANSACTIONS In connection with the sale of its Eagle Ford assets in 2017, Anadarko remained the primary counterparty to the Partnership’s Brasada gas processing agreement and entered into an agency relationship with Sanchez Energy Corporation (“Sanchez”), now Mesquite Energy, Inc. (“Mesquite”) that allows Mesquite to process gas under such agreement. For this reason, Anadarko continues to be liable under the Brasada gas processing agreement through 2034 to the extent Mesquite does not perform. For all periods presented, Mesquite has performed Anadarko’s obligations under the Brasada gas processing agreement pursuant to its agency arrangement with Anadarko. Further, in connection with the sale of its Uinta Basin assets in 2020, Kerr McGee Oil & Gas Onshore LP, a subsidiary of Occidental, retained the deficiency payment obligations under a gas processing agreement at the Chipeta plant. This contingent payment obligation extends through the earlier of October 1, 2022, or the termination of the processing agreement. Commodity purchase and sale agreements. Through December 31, 2020, the Partnership purchased and sold a significant amount of natural gas and NGLs from and 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). 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, subject to the option to extend such services for an additional six - month period. The Marketing Transition Services Agreement was terminated on December 31, 2020. While the Partnership still has some marketing agreements with affiliates of Occidental, the Partnership began marketing and selling substantially all of its natural gas and NGLs directly to third parties beginning on January 1, 2021. Operating lease. As a result of the surface - use and salt - water disposal agreements being amended under the CUA (see Related-party Commercial Agreement below), these agreements are now classified as operating leases and a $30.0 million ROU asset was recognized during the first quarter of 2021. The ROU asset will be amortized to Operation and maintenance expense over the remaining term of the agreements. Effective December 31, 2019, an affiliate of Occidental and a wholly owned subsidiary of the Partnership, the lessor, 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. In April 2021, the Partnership exercised its option to terminate the operating and maintenance agreement with Occidental effective December 31, 2021. For each of the three months ended March 31, 2021 and 2020, the Partnership recognized fixed - lease revenues of $43.9 million and variable - lease revenue of $(1.1) million and $15.6 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 Related-party expenses. Operation and maintenance expense includes amounts accrued for or paid to related parties for field - related costs provided by related parties at certain of the Partnership’s assets. 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. Cost of product expense includes amounts related to certain continuing marketing arrangements with affiliates of Occidental, related - party imbalances, and transactions with affiliates accounted for under the equity method of accounting. See Commodity purchase and sale agreements and Marketing Transition Services Agreement in the sections above. 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. Services Agreement. General and administrative expense includes costs incurred pursuant to the Services Agreement, under which Occidental has performed certain centralized corporate functions for the Partnership and WES Operating. 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 was reimbursed for the services provided by the seconded employees. 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. In late March 2020, seconded employees’ employment was transferred to the Partnership. Occidental continues to provide certain limited administrative and operational services to the Partnership, with most services expected to be fully transitioned to the Partnership by December 31, 2021. Incentive Plans. General and administrative expense includes non - cash 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 allocated expense related to the Incentive Plans of $3.2 million and $4.1 million for the three months ended March 31, 2021 and 2020, respectively. These amounts are reflected as contributions to partners’ capital in the consolidated statements of equity and partners’ capital. Related-party Commercial Agreement. During the first quarter of 2021, an affiliate of Occidental and certain wholly owned subsidiaries of the Partnership entered into a Commercial Understanding Agreement (“CUA”). Under the CUA, certain West Texas surface - use and salt - water disposal agreements were amended to reduce usage fees owed by the Partnership in exchange for the forgiveness of certain deficiency fees owed by Occidental and other unrelated contractual amendments. The present value of the reduced usage fees under the CUA was $30.0 million. Anadarko note receivable. In May 2008, WES Operating loaned $260.0 million to Anadarko in exchange for a 30 - year note that bore interest at a fixed annual rate and was classified as interest income in the consolidated statements of operations. On September 11, 2020, the Partnership and Occidental entered into a Unit Redemption Agreement, pursuant to which WES Operating transferred the note receivable to Anadarko, which Anadarko immediately canceled and retired upon receipt. Purchases from related parties. During the fourth quarter of 2020, a subsidiary of the Partnership entered into an agreement to purchase three electrical substations located in the DJ Basin from a subsidiary of Occidental for $2.0 million. This purchase was recorded as an Accrued capital expenditure as of December 31, 2020, and cash was paid in January of 2021. 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	3 Months Ended
	Mar. 31, 2021
Equity Method Investments and Joint Ventures [Abstract]
Equity Investments	7. EQUITY INVESTMENTS The following table presents the financial statement impact of the Partnership’s equity investments for the three months ended March 31, 2021: thousands Balance at December 31, 2020 Equity Contributions Distributions Distributions in excess of cumulative earnings (1) Balance at March 31, 2021 White Cliffs $ 45,623 $ 381 $ — $ (236) $ (2,644) $ 43,124 Rendezvous 28,198 (145) — (341) (539) 27,173 Mont Belvieu JV 98,874 6,718 — (6,400) — 99,192 TEG 16,661 1,107 — (1,116) (129) 16,523 TEP 195,189 9,161 — (6,506) (4,491) 193,353 FRP 199,881 8,723 — (8,767) (3,369) 196,468 Whitethorn LLC 156,729 2,085 31 (1,799) (761) 156,285 Cactus II 173,921 6,259 55 (3,835) — 176,400 Saddlehorn 111,717 8,434 — (8,063) — 112,088 Panola 20,867 655 — (655) (152) 20,715 Mi Vida 55,031 2,055 — (2,080) (56) 54,950 Ranch Westex 18,898 3,357 — (6,348) — 15,907 Red Bluff Express 103,224 3,375 — (2,902) — 103,697 Total $ 1,224,813 $ 52,165 $ 86 $ (49,048) $ (12,141) $ 1,215,875 _________________________________________________________________________________________ (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	3 Months Ended
	Mar. 31, 2021
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 March 31, December 31, Land N/A $ 9,741 $ 9,696 Gathering systems – pipelines 30 years 5,286,821 5,231,212 Gathering systems – compressors 15 years 2,133,889 2,096,905 Processing complexes and treating facilities 25 years 3,434,442 3,424,368 Transportation pipeline and equipment 6 to 45 years 168,205 168,205 Produced - water disposal systems 20 years 844,794 831,719 Assets under construction N/A 94,005 176,834 Other 3 to 40 years 717,541 702,806 Total property, plant, and equipment 12,689,438 12,641,745 Less accumulated depreciation 4,049,900 3,931,800 Net property, plant, and equipment $ 8,639,538 $ 8,709,945 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 and other impairments. During the three months ended March 31, 2021, the Partnership recognized impairments of $14.9 million, primarily attributable to $13.5 million of impairments at the DJ Basin complex due to cancellation of projects. During the three months ended March 31, 2020, the Partnership recognized impairments of $155.8 million, primarily due to $145.1 million of impairments for assets located in Wyoming and Utah. These assets were impaired to estimated fair values of $91.0 million and estimated salvage value of $6.7 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 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 $10.7 million were primarily at the DJ Basin complex due to cancellation of projects and impairments of rights - of - way. Potential future long-lived asset impairments. As of March 31, 2021, it is reasonably possible that future commodity - price declines, prolonged depression of commodity prices, changes to producers’ drilling plans in response to lower prices, and potential producer bankruptcies could result in future long - lived asset impairments. For example, on April 29, 2020, the Partnership received notice that Sanchez, in its bankruptcy, is attempting to reject a number of midstream and downstream agreements with commercial counterparties, including Sanchez’s Springfield gathering agreements and agreements obligating Sanchez to deliver the gas volumes gathered by the Springfield system to our Brasada processing plant. On May 6, 2021, the Bankruptcy Court issued an opinion determining, among other things, that Sanchez’s Springfield gathering agreements were rejected, but that such agreements contain covenants running with the land that survive rejection, thus preserving the acreage dedication to the Partnership’s Springfield system. Depending on the ultimate outcome of the Partnership’s continuing efforts to defend its contractual rights in the bankruptcy proceeding, as well as the Partnership’s ongoing commercial discussions, the Partnership’s South Texas assets could be impaired.

Goodwill

Goodwill	3 Months Ended
	Mar. 31, 2021
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 at the reporting - unit level on an annual basis, 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 value 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 value of goodwill for the gathering and processing reporting unit to zero. Goodwill allocated to the transportation reporting unit of $4.8 million as of March 31, 2020, was not impaired. Recurring goodwill impairment assessments have indicated no further impairment.

Selected Components of Working

Selected Components of Working Capital	3 Months Ended
	Mar. 31, 2021
Selected Components Of Working Capital [Abstract]
Selected Components of Working Capital	10. SELECTED COMPONENTS OF WORKING CAPITAL A summary of accounts receivable, net is as follows: The Partnership WES Operating thousands March 31, December 31, March 31, December 31, Trade receivables, net $ 480,265 $ 452,718 $ 457,998 $ 407,547 Other receivables, net 440 162 91 2 Total accounts receivable, net $ 480,705 $ 452,880 $ 458,089 $ 407,549 A summary of other current assets is as follows: The Partnership WES Operating thousands March 31, December 31, March 31, December 31, NGLs inventory $ 4,373 $ 882 $ 4,373 $ 882 Imbalance receivables 29,723 12,976 29,723 12,976 Prepaid insurance 6,741 8,131 5,150 6,113 Contract assets 14,745 5,338 14,745 5,338 Other 18,497 17,935 18,497 17,935 Total other current assets $ 74,079 $ 45,262 $ 72,488 $ 43,244 A summary of accrued liabilities is as follows: The Partnership WES Operating thousands March 31, December 31, March 31, December 31, Accrued interest expense $ 73,940 $ 137,307 $ 73,940 $ 137,307 Short - term asset retirement obligations 16,181 20,215 16,181 20,215 Short - term remediation and reclamation obligations 5,951 2,950 5,951 2,950 Income taxes payable 3,023 3,399 3,023 3,399 Contract liabilities 19,250 31,477 19,250 31,477 Other (1) 81,840 74,599 55,818 35,485 Total accrued liabilities $ 200,185 $ 269,947 $ 174,163 $ 230,833 _________________________________________________________________________________________ (1) As of March 31, 2021, includes $29.1 million of field - related accruals owed to related parties, portions of which include the weather - related impacts caused by winter storm Uri.

Debt and Interest Expense

Debt and Interest Expense	3 Months Ended
	Mar. 31, 2021
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: March 31, 2021 December 31, 2020 thousands Principal Carrying Fair Value (1) Principal Carrying Fair Value (1) Short - term debt 5.375% Senior Notes due 2021 $ — $ — $ — $ 431,081 $ 430,606 $ 436,241 Finance lease liabilities 7,752 7,752 7,752 8,264 8,264 8,264 Total short - term debt $ 7,752 $ 7,752 $ 7,752 $ 439,345 $ 438,870 $ 444,505 Long - term debt 4.000% Senior Notes due 2022 $ 580,917 $ 580,613 $ 596,358 $ 580,917 $ 580,555 $ 597,568 Floating - Rate Senior Notes due 2023 239,978 239,013 237,964 239,978 238,879 235,066 3.100% Senior Notes due 2025 1,000,000 993,300 1,035,754 1,000,000 992,900 1,028,614 3.950% Senior Notes due 2025 500,000 495,132 514,220 500,000 494,866 512,807 4.650% Senior Notes due 2026 500,000 496,840 527,584 500,000 496,708 524,880 4.500% Senior Notes due 2028 400,000 395,746 415,374 400,000 395,617 415,454 4.750% Senior Notes due 2028 400,000 396,649 418,284 400,000 396,555 418,786 4.050% Senior Notes due 2030 1,200,000 1,189,637 1,304,379 1,200,000 1,189,407 1,342,996 5.450% Senior Notes due 2044 600,000 593,631 617,579 600,000 593,598 607,234 5.300% Senior Notes due 2048 700,000 687,101 703,739 700,000 687,048 694,172 5.500% Senior Notes due 2048 350,000 342,571 342,609 350,000 342,543 343,928 5.250% Senior Notes due 2050 1,000,000 983,561 1,082,044 1,000,000 983,512 1,100,375 Finance lease liabilities 22,207 22,207 22,207 23,644 23,644 23,644 Total long - term debt $ 7,493,102 $ 7,416,001 $ 7,818,095 $ 7,494,539 $ 7,415,832 $ 7,845,524 _________________________________________________________________________________________ (1) Fair value is measured using the market approach and Level - 2 fair value inputs. 11. DEBT AND INTEREST EXPENSE Debt activity. The following table presents the debt activity for the three months ended March 31, 2021: thousands Carrying Value Balance at December 31, 2020 $ 7,854,702 RCF borrowings 100,000 Repayments of RCF borrowings (100,000) Repayment of 5.375% Senior Notes due 2021 (431,081) Finance lease liabilities (1,949) Other 2,081 Balance at March 31, 2021 $ 7,423,753 WES Operating Senior Notes. In mid - January 2020, WES Operating issued the Fixed - Rate 3.100% Senior Notes due 2025, 4.050% Senior Notes due 2030, and 5.250% Senior Notes due 2050 (collectively referred to as the “Fixed - Rate Senior Notes”) and the Floating - Rate Senior Notes due 2023 (the “Floating - Rate Senior Notes”). Including the effects of the issuance prices, underwriting discounts, and interest - rate adjustments, the effective interest rates of the Senior Notes due 2025, 2030, and 2050, were 4.542%, 5.424%, and 6.629%, respectively, at March 31, 2021, and were 3.287%, 4.168%, and 5.362%, respectively, at March 31, 2020. The interest rate on the Floating - Rate Senior Notes was 2.33% and 2.69% at March 31, 2021 and 2020, respectively. The effective interest rate of these notes is subject to adjustment from time to time due to a change in credit rating. During the first quarter of 2021, WES Operating redeemed the total principal amount outstanding of the 5.375% Senior Notes due 2021 at par value, pursuant to the optional redemption terms in WES Operating’s indenture. At March 31, 2021, WES Operating was in compliance with all covenants under the relevant governing indentures. Revolving credit facility. WES Operating’s $2.0 billion senior unsecured revolving credit facility (“RCF”) is expandable to a maximum of $2.5 billion, and matures in February 2025 for each extending lender. The non - extending lender’s commitments mature in February 2024 and represent $100.0 million out of $2.0 billion of total commitments from all lenders. As of March 31, 2021, there were no outstanding borrowings and $5.1 million of outstanding letters of credit, resulting in $2.0 billion of available borrowing capacity under the RCF. As of March 31, 2021 and 2020, the interest rate on any outstanding RCF borrowings was 1.61% and 2.13%, respectively. The facility - fee rate was 0.25% and 0.20% at March 31, 2021 and 2020, respectively. At March 31, 2021, WES Operating was in compliance with all covenants under the RCF. Term loan facility. 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 its $3.0 billion senior unsecured credit facility (“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 $34.5 million as of March 31, 2021. 11. DEBT AND INTEREST EXPENSE Interest expense. The following table summarizes the amounts included in interest expense: Three Months Ended thousands 2021 2020 Third parties Long - term and short - term debt $ (95,722) $ (89,769) Finance lease liabilities (298) (405) Amortization of debt issuance costs and commitment fees (3,338) (3,127) Capitalized interest 865 4,758 Total interest expense – third parties (98,493) (88,543) Related parties Finance lease liabilities — (43) Total interest expense – related parties — (43) Interest expense $ (98,493) $ (88,586)

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
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 payment obligations, or commitments, that include, among other things, a revolving credit facility, other third - party long - term debt, obligations related to the Partnership’s capital spending programs, pipeline commitments, and various operating and finance leases. The payment obligations related to the Partnership’s capital spending programs, the majority of which is expected to be paid in the next twelve months, primarily relate to construction, expansion, and asset - integrity projects at the West Texas complex, DBM water systems, DJ Basin complex, and DBM oil system.

Description of Business and B_2

Description of Business and Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2021
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”) and include the accounts of the Partnership and entities in which it holds a controlling financial interest, including WES Operating, WES Operating GP, proportionately consolidated interests, and equity investments (see table below). 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 JV LLC (“Mi Vida”) 50.00 % Ranch Westex JV LLC (“Ranch Westex”) 50.00 % Front Range Pipeline LLC (“FRP”) 33.33 % Red Bluff Express Pipeline, LLC (“Red Bluff Express”) 30.00 % Enterprise EF78 LLC (“Mont Belvieu JV”) 25.00 % Rendezvous Gas Services, LLC (“Rendezvous”) 22.00 % Texas Express Pipeline LLC (“TEP”) 20.00 % Texas Express Gathering LLC (“TEG”) 20.00 % Whitethorn Pipeline Company LLC (“Whitethorn LLC”) 20.00 % Saddlehorn Pipeline Company, LLC (“Saddlehorn”) 20.00 % Cactus II Pipeline LLC (“Cactus II”) 15.00 % Panola Pipeline Company, LLC (“Panola”) 15.00 % White Cliffs Pipeline, LLC (“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. Certain information and note disclosures commonly included in annual financial statements have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Accordingly, the accompanying consolidated financial statements and notes should be read in conjunction with the Partnership’s 2020 Form 10 - K, as filed with the SEC on February 26, 2021. Management believes that the disclosures made are adequate to make the information not misleading. 1. DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION 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), (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, and (iv) the inclusion of the impact of Partnership equity balances and Partnership distributions. Noncontrolling interests. 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. WES Operating’s noncontrolling interest in the consolidated financial statements consists of the 25% third - party interest in Chipeta. See Note 5.
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.
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.
Net income (loss) per common unit policy	Partnership’s net income (loss) per common unit. 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 (beyond proper reserves 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. WES Operating’s net income (loss) per common unit. Net income (loss) per common unit for WES Operating is not calculated because it has no publicly traded units.
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 at the reporting - unit level on an annual basis, 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 value 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.

Description of Business and B_3

Description of Business and Basis of Presentation (Tables)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Assets and Investments Table	As of March 31, 2021, the Partnership’s assets and investments consisted of the following: Wholly Operated Non-Operated Equity Gathering systems (1) 17 2 3 1 Treating facilities 39 3 — — Natural - gas processing plants/trains 25 3 — 5 NGLs pipelines 2 — — 5 Natural - gas pipelines 5 — — 1 Crude - oil pipelines 3 1 — 4 _________________________________________________________________________________________ (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 JV LLC (“Mi Vida”) 50.00 % Ranch Westex JV LLC (“Ranch Westex”) 50.00 % Front Range Pipeline LLC (“FRP”) 33.33 % Red Bluff Express Pipeline, LLC (“Red Bluff Express”) 30.00 % Enterprise EF78 LLC (“Mont Belvieu JV”) 25.00 % Rendezvous Gas Services, LLC (“Rendezvous”) 22.00 % Texas Express Pipeline LLC (“TEP”) 20.00 % Texas Express Gathering LLC (“TEG”) 20.00 % Whitethorn Pipeline Company LLC (“Whitethorn LLC”) 20.00 % Saddlehorn Pipeline Company, LLC (“Saddlehorn”) 20.00 % Cactus II Pipeline LLC (“Cactus II”) 15.00 % Panola Pipeline Company, LLC (“Panola”) 15.00 % White Cliffs Pipeline, LLC (“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)	3 Months Ended
	Mar. 31, 2021
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 thousands 2021 2020 Revenue from customers Service revenues – fee based $ 529,413 $ 641,921 Service revenues – product based 31,652 15,921 Product sales 70,805 56,649 Total revenue from customers 631,870 714,491 Revenue from other than customers Lease revenue (1) 42,862 59,475 Other 242 347 Total revenues and other $ 674,974 $ 774,313 _________________________________________________________________________________________ (1) 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 activity related to contract assets from contracts with customers: thousands Contract assets balance at December 31, 2020 $ 56,344 Additional estimated revenues recognized 4,571 Contract assets balance at March 31, 2021 $ 60,915 Contract assets at March 31, 2021 Other current assets $ 14,745 Other assets 46,170 Total contract assets from contracts with customers $ 60,915 thousands Contract liabilities balance at December 31, 2020 $ 266,937 Cash received or receivable, excluding revenues recognized during the period 15,260 Revenues recognized that were included in the contract liability balance at the beginning of the period (2,067) Contract liabilities balance at March 31, 2021 $ 280,130 Contract liabilities at March 31, 2021 Accrued liabilities $ 19,250 Other liabilities 260,880 Total contract liabilities from contracts with customers $ 280,130
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 2021 $ 618,392 2022 1,055,916 2023 1,000,434 2024 971,137 2025 888,850 Thereafter 2,715,378 Total $ 7,250,107

Partnership Distributions (Tabl

Partnership Distributions (Tables)	3 Months Ended
	Mar. 31, 2021
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 2020 March 31 $ 0.31100 $ 140,893 May 2020 June 30 0.31100 140,900 August 2020 September 30 0.31100 132,255 November 2020 December 31 0.31100 131,265 February 2021 2021 March 31 (1) $ 0.31500 $ 132,969 May 2021 _________________________________________________________________________________________ (1) The Board of Directors declared a cash distribution to the Partnership’s unitholders for the first quarter of 2021 of $0.31500 per unit, or $133.0 million in aggregate. The cash distribution is payable on May 14, 2021 to unitholders of record at the close of business on April 30, 2021, including the general partner units. thousands Quarters Ended Total Quarterly 2020 March 31 $ 143,404 June 30 143,404 September 30 143,404 December 31 127,470 2021 March 31 $ 137,030

Related-Party Transactions (Tab

Related-Party Transactions (Tables)	3 Months Ended
	Mar. 31, 2021
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 thousands 2021 2020 Revenues and other Service revenues – fee based $ 367,475 $ 447,783 Service revenues – product based 4,505 2,978 Product sales 6,271 31,624 Total revenues and other 378,251 482,385 Equity income, net – related parties (1) 52,165 61,347 Operating expenses Cost of product 17,647 77,903 Operation and maintenance 18,122 32,841 General and administrative (2) 4,093 21,855 Total operating expenses 39,862 132,599 Interest income – Anadarko note receivable — 4,225 Interest expense — (43) _________________________________________________________________________________________ (1) See Note 7 . (2) Includes (i) amounts charged by Occidental pursuant to the shared services agreement (see Services Agreement within this Note 6 ) and (ii) equity - based compensation expense allocated to the Partnership by Occidental, which is not reimbursed to Occidental and is reflected as a contribution to partners’ capital in the consolidated statements of equity and partners’ capital (see Incentive Plans within this Note 6 ). 6. RELATED-PARTY TRANSACTIONS Consolidated balance sheets thousands March 31, December 31, Assets Accounts receivable, net $ 253,553 $ 291,253 Other current assets 14,096 5,493 Equity investments (1) 1,215,875 1,224,813 Other assets (2) 46,124 50,967 Total assets 1,529,648 1,572,526 Liabilities Accounts and imbalance payables 8,929 6,664 Accrued liabilities 52,779 19,195 Other liabilities 153,841 138,796 Total liabilities 215,549 164,655 _________________________________________________________________________________________ (1) See Note 7 . (2) For the three months ended March 31, 2021, includes the addition of a $30.0 million right - of - use (“ROU”) asset recognized in connection with related - party operating leases (see Operating lease within this Note 6) . Consolidated statements of cash flows Three Months Ended thousands 2021 2020 Distributions from equity - investment earnings – related parties $ 49,048 $ 60,868 Acquisitions from related parties (2,000) — Contributions to equity investments – related parties (86) (10,960) Distributions from equity investments in excess of cumulative earnings – related parties 12,141 5,052 Distributions to Partnership unitholders (1) (66,642) (150,609) Distributions to WES Operating unitholders (2) (2,551) (5,807) Net contributions from (distributions to) related parties 1,627 20,489 Finance lease payments — (202) _________________________________________________________________________________________ (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 a certain subsidiary 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 thousands 2021 2020 General and administrative (1) $ 4,587 $ 21,738 _________________________________________________________________________________________ (1) Includes (i) amounts charged by Occidental pursuant to the shared services agreement (see Services Agreement within this Note 6 ) and (ii) equity - based compensation expense allocated to WES Operating by Occidental, which is not reimbursed to Occidental and is reflected as a contribution to partners’ capital in the consolidated statements of equity and partners’ capital (see Incentive Plans within this Note 6 ). Consolidated balance sheets thousands March 31, December 31, Accounts receivable, net $ 231,286 $ 246,083 Consolidated statements of cash flows Three Months Ended thousands 2021 2020 Distributions to WES Operating unitholders (1) $ (127,470) $ (290,314) _________________________________________________________________________________________ (1) Represents distributions paid to the Partnership and a certain subsidiary of Occidental pursuant to WES Operating’s partnership agreement (see Note 4 and Note 5 ).

Equity Investments (Tables)

Equity Investments (Tables)	3 Months Ended
	Mar. 31, 2021
Equity Method Investments and Joint Ventures [Abstract]
Equity Investments Table	The following table presents the financial statement impact of the Partnership’s equity investments for the three months ended March 31, 2021: thousands Balance at December 31, 2020 Equity Contributions Distributions Distributions in excess of cumulative earnings (1) Balance at March 31, 2021 White Cliffs $ 45,623 $ 381 $ — $ (236) $ (2,644) $ 43,124 Rendezvous 28,198 (145) — (341) (539) 27,173 Mont Belvieu JV 98,874 6,718 — (6,400) — 99,192 TEG 16,661 1,107 — (1,116) (129) 16,523 TEP 195,189 9,161 — (6,506) (4,491) 193,353 FRP 199,881 8,723 — (8,767) (3,369) 196,468 Whitethorn LLC 156,729 2,085 31 (1,799) (761) 156,285 Cactus II 173,921 6,259 55 (3,835) — 176,400 Saddlehorn 111,717 8,434 — (8,063) — 112,088 Panola 20,867 655 — (655) (152) 20,715 Mi Vida 55,031 2,055 — (2,080) (56) 54,950 Ranch Westex 18,898 3,357 — (6,348) — 15,907 Red Bluff Express 103,224 3,375 — (2,902) — 103,697 Total $ 1,224,813 $ 52,165 $ 86 $ (49,048) $ (12,141) $ 1,215,875 _________________________________________________________________________________________ (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)	3 Months Ended
	Mar. 31, 2021
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 March 31, December 31, Land N/A $ 9,741 $ 9,696 Gathering systems – pipelines 30 years 5,286,821 5,231,212 Gathering systems – compressors 15 years 2,133,889 2,096,905 Processing complexes and treating facilities 25 years 3,434,442 3,424,368 Transportation pipeline and equipment 6 to 45 years 168,205 168,205 Produced - water disposal systems 20 years 844,794 831,719 Assets under construction N/A 94,005 176,834 Other 3 to 40 years 717,541 702,806 Total property, plant, and equipment 12,689,438 12,641,745 Less accumulated depreciation 4,049,900 3,931,800 Net property, plant, and equipment $ 8,639,538 $ 8,709,945

Selected Components of Workin_2

Selected Components of Working Capital (Tables)	3 Months Ended
	Mar. 31, 2021
Selected Components Of Working Capital [Abstract]
Accounts Receivable, Net Table	A summary of accounts receivable, net is as follows: The Partnership WES Operating thousands March 31, December 31, March 31, December 31, Trade receivables, net $ 480,265 $ 452,718 $ 457,998 $ 407,547 Other receivables, net 440 162 91 2 Total accounts receivable, net $ 480,705 $ 452,880 $ 458,089 $ 407,549
Other Current Assets Table	A summary of other current assets is as follows: The Partnership WES Operating thousands March 31, December 31, March 31, December 31, NGLs inventory $ 4,373 $ 882 $ 4,373 $ 882 Imbalance receivables 29,723 12,976 29,723 12,976 Prepaid insurance 6,741 8,131 5,150 6,113 Contract assets 14,745 5,338 14,745 5,338 Other 18,497 17,935 18,497 17,935 Total other current assets $ 74,079 $ 45,262 $ 72,488 $ 43,244
Accrued Liabilities Table	A summary of accrued liabilities is as follows: The Partnership WES Operating thousands March 31, December 31, March 31, December 31, Accrued interest expense $ 73,940 $ 137,307 $ 73,940 $ 137,307 Short - term asset retirement obligations 16,181 20,215 16,181 20,215 Short - term remediation and reclamation obligations 5,951 2,950 5,951 2,950 Income taxes payable 3,023 3,399 3,023 3,399 Contract liabilities 19,250 31,477 19,250 31,477 Other (1) 81,840 74,599 55,818 35,485 Total accrued liabilities $ 200,185 $ 269,947 $ 174,163 $ 230,833 _________________________________________________________________________________________ (1) As of March 31, 2021, includes $29.1 million of field - related accruals owed to related parties, portions of which include the weather - related impacts caused by winter storm Uri.

Debt and Interest Expense (Tabl

Debt and Interest Expense (Tables)	3 Months Ended
	Mar. 31, 2021
Debt Instruments [Abstract]
Debt Outstanding and Debt Activity Tables	The following table presents the outstanding debt: March 31, 2021 December 31, 2020 thousands Principal Carrying Fair Value (1) Principal Carrying Fair Value (1) Short - term debt 5.375% Senior Notes due 2021 $ — $ — $ — $ 431,081 $ 430,606 $ 436,241 Finance lease liabilities 7,752 7,752 7,752 8,264 8,264 8,264 Total short - term debt $ 7,752 $ 7,752 $ 7,752 $ 439,345 $ 438,870 $ 444,505 Long - term debt 4.000% Senior Notes due 2022 $ 580,917 $ 580,613 $ 596,358 $ 580,917 $ 580,555 $ 597,568 Floating - Rate Senior Notes due 2023 239,978 239,013 237,964 239,978 238,879 235,066 3.100% Senior Notes due 2025 1,000,000 993,300 1,035,754 1,000,000 992,900 1,028,614 3.950% Senior Notes due 2025 500,000 495,132 514,220 500,000 494,866 512,807 4.650% Senior Notes due 2026 500,000 496,840 527,584 500,000 496,708 524,880 4.500% Senior Notes due 2028 400,000 395,746 415,374 400,000 395,617 415,454 4.750% Senior Notes due 2028 400,000 396,649 418,284 400,000 396,555 418,786 4.050% Senior Notes due 2030 1,200,000 1,189,637 1,304,379 1,200,000 1,189,407 1,342,996 5.450% Senior Notes due 2044 600,000 593,631 617,579 600,000 593,598 607,234 5.300% Senior Notes due 2048 700,000 687,101 703,739 700,000 687,048 694,172 5.500% Senior Notes due 2048 350,000 342,571 342,609 350,000 342,543 343,928 5.250% Senior Notes due 2050 1,000,000 983,561 1,082,044 1,000,000 983,512 1,100,375 Finance lease liabilities 22,207 22,207 22,207 23,644 23,644 23,644 Total long - term debt $ 7,493,102 $ 7,416,001 $ 7,818,095 $ 7,494,539 $ 7,415,832 $ 7,845,524 _________________________________________________________________________________________ (1) Fair value is measured using the market approach and Level - 2 fair value inputs. 11. DEBT AND INTEREST EXPENSE Debt activity. The following table presents the debt activity for the three months ended March 31, 2021: thousands Carrying Value Balance at December 31, 2020 $ 7,854,702 RCF borrowings 100,000 Repayments of RCF borrowings (100,000) Repayment of 5.375% Senior Notes due 2021 (431,081) Finance lease liabilities (1,949) Other 2,081 Balance at March 31, 2021 $ 7,423,753
Interest Expense Table	The following table summarizes the amounts included in interest expense: Three Months Ended thousands 2021 2020 Third parties Long - term and short - term debt $ (95,722) $ (89,769) Finance lease liabilities (298) (405) Amortization of debt issuance costs and commitment fees (3,338) (3,127) Capitalized interest 865 4,758 Total interest expense – third parties (98,493) (88,543) Related parties Finance lease liabilities — (43) Total interest expense – related parties — (43) Interest expense $ (98,493) $ (88,586)

Description of Business and B_4

Description of Business and Basis of Presentation - Assets and Investments Table (Details)	Mar. 31, 2021unit
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	39
Wholly Owned and Operated [Member] | Natural-Gas Processing Plants/Trains [Member]
Assets [Line Items]
Assets, number of units	25
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	1
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	5
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	4

Description of Business and B_5

Description of Business and Basis of Presentation - Ownership Interests and Method of Consolidation Table (Details)	3 Months Ended
	Mar. 31, 2021
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 Interests [Member] | Mi Vida [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity-investment ownership percentage	50.00%
Equity Interests [Member] | Ranch Westex [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity-investment ownership percentage	50.00%
Equity Interests [Member] | Front Range Pipeline [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity-investment ownership percentage	33.33%
Equity Interests [Member] | Red Bluff Express Pipeline Limited Liability Company [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity-investment ownership percentage	30.00%
Equity Interests [Member] | Mont Belvieu JV [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity-investment ownership percentage	25.00%
Equity Interests [Member] | Rendezvous [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity-investment ownership percentage	22.00%
Equity Interests [Member] | Texas Express Pipeline [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity-investment ownership percentage	20.00%
Equity Interests [Member] | Texas Express Gathering [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity-investment ownership percentage	20.00%
Equity Interests [Member] | Whitethorn LLC [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity-investment ownership percentage	20.00%
Equity Interests [Member] | Saddlehorn [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity-investment ownership percentage	20.00%
Equity Interests [Member] | Cactus II [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity-investment ownership percentage	15.00%
Equity Interests [Member] | Panola [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Equity-investment ownership percentage	15.00%
Equity Interests [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 ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 22, 2021
Defined-contribution plan expense	$ 6.9	$ 0.4
Western Gas Equity Partners 2012 Long-Term Incentive Plan [Member]
Common units issued under the WES LTIP, number of units	338,078
Equity-based compensation expense	$ 3.5	$ 1.1
Western Midstream Partners, LP 2021 Long-Term Incentive Plan [Member]
Units authorized under LTIP			9,500,000
WES Operating [Member]
Ownership interest by noncontrolling interest owner	2.00%
Chipeta [Member]
Ownership interest by noncontrolling interest owner	25.00%
WES [Member] | WES Operating [Member]
Ownership interest	98.00%

Revenue from Contracts with C_3

Revenue from Contracts with Customers - Revenue From Contracts With Customers Table (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Revenue from customers		$ 631,870	$ 714,491
Revenue from other than customers, other		242	347
Total revenues and other	[1]	674,974	774,313
Service Revenues - Fee Based [Member]
Disaggregation of Revenue [Line Items]
Revenue from customers		529,413	641,921
Total revenues and other		572,275	701,396
Service Revenues - Product Based [Member]
Disaggregation of Revenue [Line Items]
Revenue from customers		31,652	15,921
Total revenues and other		31,652	15,921
Product Sales [Member]
Disaggregation of Revenue [Line Items]
Revenue from customers		70,805	56,649
Total revenues and other		70,805	56,649
Lease Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue from other than customers		$ 42,862	$ 59,475
[1]	Total revenues and other includes related - party amounts of $378.3 million and $482.4 million for the three months ended March 31, 2021 and 2020, 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
	Mar. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Change in Contracts with Customer, Asset [Roll Forward]
Contract assets balance at beginning of year	$ 56,344
Additional estimated revenues recognized	4,571
Contract assets balance at end of year	60,915
Contract Assets [Abstract]
Other current assets		$ 14,745	$ 5,338
Other assets		46,170
Total contract assets from contracts with customers	$ 60,915	$ 60,915	$ 56,344

Revenue from Contracts with C_5

Revenue from Contracts with Customers - Contract Liabilities Table (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Change in Contracts with Customer, Liability [Roll Forward]
Contract liabilities balance at begining of year	$ 266,937
Cash received or receivable, excluding revenues recognized during the period	15,260
Revenues recognized that were included in the contract liability balance at the beginning of the period	(2,067)
Contract liabilities balance at end of year	280,130
Contract with Customer, Liability [Abstract]
Accrued liabilities		$ 19,250	$ 31,477
Other liabilities		260,880
Total contract liabilities from contracts with customers	$ 280,130	$ 280,130	$ 266,937

Revenue from Contracts with C_6

Revenue from Contracts with Customers - Expected Revenues Table (Details) $ in Thousands	Mar. 31, 2021USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligation expected to be satisfied	$ 7,250,107
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligation expected to be satisfied	$ 618,392
Performance obligation expected to be satisfied, expected timing	9 months
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	$ 1,055,916
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	$ 1,000,434
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	$ 971,137
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	$ 888,850
Performance obligation expected to be satisfied, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligation expected to be satisfied	$ 2,715,378
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	Mar. 31, 2021	Dec. 31, 2020
Revenue from Contracts with Customer [Line Items]
Accounts receivable, net	$ 480,705	$ 452,880
Customers [Member]
Revenue from Contracts with Customer [Line Items]
Accounts receivable, net	$ 469,300	$ 428,200

Acquisitions and Divestitures -

Acquisitions and Divestitures - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2020	Oct. 09, 2020
Fort Union [Member]
Property, Plant and Equipment [Line Items]
Equity-investment ownership percentage		14.81%
Net gain on sale of assets	$ 21
Fort Union and Bison Treating Facility [Member]
Property, Plant and Equipment [Line Items]
Proceeds from sale of assets	$ 27

Partnership Distributions - Cas

Partnership Distributions - Cash Distributions Tables (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020
Distribution Made to Limited Partner [Line Items]
Total quarterly per-unit distribution	$ 0.31500	$ 0.31100	$ 0.31100	$ 0.31100	$ 0.31100
Total quarterly cash distribution	$ 132,969	$ 131,265	$ 132,255	$ 140,900	$ 140,893
WES Operating [Member]
Distribution Made to Limited Partner [Line Items]
Total quarterly cash distribution	$ 137,030	$ 127,470	$ 143,404	$ 143,404	$ 143,404

Partnership Distributions - Add

Partnership Distributions - Additional Information (Details)	3 Months Ended
	Mar. 31, 2021
WES [Member]
Distribution Made to Limited Partner [Line Items]
Partnership agreement day requirement of distribution of available cash	55 days

Equity and Partners' Capital -

Equity and Partners' Capital - Additional Information (Details) - USD ($)	Sep. 11, 2020	Mar. 31, 2021	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	May 31, 2008
Schedule of Investments [Line Items]
Common units outstanding		413,062,133	413,062,133		413,839,863
General partner units outstanding		9,060,641	9,060,641		9,060,641
Unit repurchases, authorized amount		$ 250,000,000	$ 250,000,000
Unit repurchases, number of units			1,115,808
Unit repurchases, amount			$ 16,241,000	$ 0
Unit repurchases, remaining authorized amount		$ 201,200,000	$ 201,200,000
WES [Member] | Public [Member]
Schedule of Investments [Line Items]
Common units outstanding		210,280,555	210,280,555
Limited partner's interest			49.80%
Related Parties [Member]
Schedule of Investments [Line Items]
Anadarko note receivable						$ 260,000,000
Anadarko [Member]
Schedule of Investments [Line Items]
Anadarko note receivable - percentage interest transferred	98.00%
Anadarko note receivable	$ 260,000,000
WES [Member] | WES Operating [Member]
Schedule of Investments [Line Items]
Limited partner's interest			98.00%
WES [Member] | Related Parties [Member] | Limited Partner [Member] | WES [Member]
Schedule of Investments [Line Items]
Units redeemed from a related party	27,855,398
Occidental [Member]
Schedule of Investments [Line Items]
Units sold by a related party		11,500,000
Units sold to by a related party, over-allotment		1,500,000
Occidental [Member] | WES [Member]
Schedule of Investments [Line Items]
Common units outstanding		202,781,578	202,781,578
Limited partner's interest			48.00%
General partner units outstanding		9,060,641	9,060,641
General partner's interest			2.20%
Occidental [Member] | WES Operating [Member]
Schedule of Investments [Line Items]
Limited partner's interest			2.00%
WES Operating [Member]
Schedule of Investments [Line Items]
Common units outstanding		318,675,578	318,675,578		318,675,578

Related-Party Transactions - Su

Related-Party Transactions - Summary of WES Related-Party Transactions Tables (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Consolidated statements of operations [Abstract]
Revenues and other	[1]	$ 674,974	$ 774,313
Equity income, net – related parties		52,165	61,347
Cost of product		88,969	103,270
Operation and maintenance		140,332	159,191
General and administrative		45,116	40,465
Operating expenses	[2]	434,220	1,050,523
Interest income – Anadarko note receivable		0	4,225
Interest expense		(98,493)	(88,586)
Consolidated balance sheets [Abstract]
Accounts receivable, net		480,705		$ 452,880
Other current assets		74,079		45,262
Equity investments		1,215,875		1,224,813
Other assets	[3]	195,195		171,013
Total assets	[4]	11,435,043		11,830,027
Accounts and imbalance payables		226,715		210,691
Accrued liabilities		200,185		269,947
Other liabilities		295,946		275,570
Total liabilities	[5]	8,492,923		8,934,815
Consolidated statements of cash flows [Abstract]
Distributions from equity-investment earnings – related parties		49,048	60,868
Contributions to equity investments – related parties		(86)	(10,960)
Distributions from equity investments in excess of cumulative earnings – related parties		12,141	5,052
Distributions to Partnership unitholders	[6]	(131,265)	(281,786)
Net contributions from (distributions to) related parties		1,627	20,489
Finance lease payments		(1,816)	(2,151)
Service Revenues - Fee Based [Member]
Consolidated statements of operations [Abstract]
Revenues and other		572,275	701,396
Service Revenues - Product Based [Member]
Consolidated statements of operations [Abstract]
Revenues and other		31,652	15,921
Product Sales [Member]
Consolidated statements of operations [Abstract]
Revenues and other		70,805	56,649
Related Parties [Member]
Consolidated statements of operations [Abstract]
Revenues and other		378,251	482,385
Cost of product		17,647	77,903
Operation and maintenance		18,122	32,841
General and administrative		4,093	21,855
Operating expenses		39,862	132,599
Interest expense		0	(43)
Consolidated balance sheets [Abstract]
Accounts receivable, net		253,553		291,253
Other current assets		14,096		5,493
Other assets		46,124		50,967
Total assets		1,529,648		1,572,526
Accounts and imbalance payables		8,929		6,664
Accrued liabilities		52,779		19,195
Other liabilities		153,841		138,796
Total liabilities		215,549		$ 164,655
Consolidated statements of cash flows [Abstract]
Acquisitions from related parties		(2,000)	0
Distributions to Partnership unitholders		(66,642)	(150,609)
Finance lease payments		0	(202)
Related Parties [Member] | WES Operating [Member]
Consolidated statements of cash flows [Abstract]
Distributions to Partnership unitholders		(2,551)	(5,807)
Related Parties [Member] | Service Revenues - Fee Based [Member]
Consolidated statements of operations [Abstract]
Revenues and other		367,475	447,783
Related Parties [Member] | Service Revenues - Product Based [Member]
Consolidated statements of operations [Abstract]
Revenues and other		4,505	2,978
Related Parties [Member] | Product Sales [Member]
Consolidated statements of operations [Abstract]
Revenues and other		6,271	$ 31,624
Occidental [Member]
Consolidated balance sheets [Abstract]
Right-of-use asset recognized		$ 30,000
[1]	Total revenues and other includes related - party amounts of $378.3 million and $482.4 million for the three months ended March 31, 2021 and 2020, respectively. See Note 6 .
[2]	Total operating expenses includes related - party amounts of $39.9 million and $132.6 million for the three months ended March 31, 2021 and 2020, respectively. See Note 6 .
[3]	Other assets includes $8.9 million and $4.2 million of NGLs line - fill inventory as of March 31, 2021, and December 31, 2020, respectively. Other assets also includes $68.5 million and $71.9 million of materials and supplies inventory as of March 31, 2021, and December 31, 2020, respectively.
[4]	Total assets includes related - party amounts of $1.5 billion and $1.6 billion as of March 31, 2021, and December 31, 2020, respectively, which includes related - party Accounts receivable, net of $253.6 million and $291.3 million as of March 31, 2021, and December 31, 2020, respectively. See Note 6 .
[5]	Total liabilities includes related - party amounts of $215.5 million and $164.7 million as of March 31, 2021, and December 31, 2020, respectively. See Note 6 .
[6]	See Note 6 .

Related-Party Transactions - _2

Related-Party Transactions - Summary of WES Operating Related-Party Transactions Tables (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Consolidated statements of operations [Abstract]
General and administrative		$ 45,116	$ 40,465
Consolidated balance sheets [Abstract]
Accounts receivable, net		480,705		$ 452,880
Consolidated statements of cash flows [Abstract]
Distributions to WES Operating unitholders	[1]	(131,265)	(281,786)
Related Parties [Member]
Consolidated statements of operations [Abstract]
General and administrative		4,093	21,855
Consolidated balance sheets [Abstract]
Accounts receivable, net		253,553		291,253
Consolidated statements of cash flows [Abstract]
Distributions to WES Operating unitholders		(66,642)	(150,609)
WES Operating [Member]
Consolidated statements of operations [Abstract]
General and administrative		44,230	39,058
Consolidated balance sheets [Abstract]
Accounts receivable, net		458,089		407,549
Consolidated statements of cash flows [Abstract]
Distributions to WES Operating unitholders	[2]	(127,470)	(290,314)
WES Operating [Member] | Related Parties [Member]
Consolidated statements of operations [Abstract]
General and administrative		4,587	21,738
Consolidated balance sheets [Abstract]
Accounts receivable, net		231,286		$ 246,083
Consolidated statements of cash flows [Abstract]
Distributions to WES Operating unitholders		$ (127,470)	$ (290,314)
[1]	See Note 6 .
[2]	See Note 6.

Related-Party Transactions - Ad

Related-Party Transactions - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	May 31, 2008
WES Operating [Member]
Related Party Transaction [Line Items]
Cash contribution from related party		$ 20,000,000
Occidental [Member]
Related Party Transaction [Line Items]
Right-of-use asset recognized	$ 30,000,000
Present value of reduced usage fees	30,000,000
Occidental [Member] | Incentive Plans [Member]
Related Party Transaction [Line Items]
Allocated equity-based compensation expense	3,200,000	4,100,000
Related Parties [Member]
Related Party Transaction [Line Items]
Operating lease, fixed-lease revenue	43,900,000	43,900,000
Operating lease, variable lease income (expense)	(1,100,000)	15,600,000
Anadarko note receivable			$ 260,000,000
Acquisitions from related parties	2,000,000	0
Related Parties [Member] | WES Operating [Member]
Related Party Transaction [Line Items]
Acquisitions from related parties	$ 2,000,000	$ 0
Natural Gas [Member]
Related Party Transaction [Line Items]
Related-party throughput percentage	35.00%	42.00%
Crude Oil and NGLs Member]
Related Party Transaction [Line Items]
Related-party throughput percentage	88.00%	89.00%
Produced water [Member]
Related Party Transaction [Line Items]
Related-party throughput percentage	86.00%	89.00%

Equity Investments - Equity Inv

Equity Investments - Equity Investments Table (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Schedule of Equity Method Investments [Line Items]
Balance	$ 1,224,813
Equity income, net	52,165	$ 61,347
Contributions	86	10,960
Distributions	(49,048)	(60,868)
Distributions from equity investments in excess of cumulative earnings – related parties	(12,141)	$ (5,052)
Balance	1,215,875
White Cliffs [Member]
Schedule of Equity Method Investments [Line Items]
Balance	45,623
Equity income, net	381
Contributions	0
Distributions	(236)
Distributions from equity investments in excess of cumulative earnings – related parties	(2,644)
Balance	43,124
Rendezvous [Member]
Schedule of Equity Method Investments [Line Items]
Balance	28,198
Equity income, net	(145)
Contributions	0
Distributions	(341)
Distributions from equity investments in excess of cumulative earnings – related parties	(539)
Balance	27,173
Mont Belvieu JV [Member]
Schedule of Equity Method Investments [Line Items]
Balance	98,874
Equity income, net	6,718
Contributions	0
Distributions	(6,400)
Distributions from equity investments in excess of cumulative earnings – related parties	0
Balance	99,192
Texas Express Gathering [Member]
Schedule of Equity Method Investments [Line Items]
Balance	16,661
Equity income, net	1,107
Contributions	0
Distributions	(1,116)
Distributions from equity investments in excess of cumulative earnings – related parties	(129)
Balance	16,523
Texas Express Pipeline [Member]
Schedule of Equity Method Investments [Line Items]
Balance	195,189
Equity income, net	9,161
Contributions	0
Distributions	(6,506)
Distributions from equity investments in excess of cumulative earnings – related parties	(4,491)
Balance	193,353
Front Range Pipeline [Member]
Schedule of Equity Method Investments [Line Items]
Balance	199,881
Equity income, net	8,723
Contributions	0
Distributions	(8,767)
Distributions from equity investments in excess of cumulative earnings – related parties	(3,369)
Balance	196,468
Whitethorn LLC [Member]
Schedule of Equity Method Investments [Line Items]
Balance	156,729
Equity income, net	2,085
Contributions	31
Distributions	(1,799)
Distributions from equity investments in excess of cumulative earnings – related parties	(761)
Balance	156,285
Cactus II [Member]
Schedule of Equity Method Investments [Line Items]
Balance	173,921
Equity income, net	6,259
Contributions	55
Distributions	(3,835)
Distributions from equity investments in excess of cumulative earnings – related parties	0
Balance	176,400
Saddlehorn [Member]
Schedule of Equity Method Investments [Line Items]
Balance	111,717
Equity income, net	8,434
Contributions	0
Distributions	(8,063)
Distributions from equity investments in excess of cumulative earnings – related parties	0
Balance	112,088
Panola [Member]
Schedule of Equity Method Investments [Line Items]
Balance	20,867
Equity income, net	655
Contributions	0
Distributions	(655)
Distributions from equity investments in excess of cumulative earnings – related parties	(152)
Balance	20,715
Mi Vida [Member]
Schedule of Equity Method Investments [Line Items]
Balance	55,031
Equity income, net	2,055
Contributions	0
Distributions	(2,080)
Distributions from equity investments in excess of cumulative earnings – related parties	(56)
Balance	54,950
Ranch Westex [Member]
Schedule of Equity Method Investments [Line Items]
Balance	18,898
Equity income, net	3,357
Contributions	0
Distributions	(6,348)
Distributions from equity investments in excess of cumulative earnings – related parties	0
Balance	15,907
Red Bluff Express Pipeline Limited Liability Company [Member]
Schedule of Equity Method Investments [Line Items]
Balance	103,224
Equity income, net	3,375
Contributions	0
Distributions	(2,902)
Distributions from equity investments in excess of cumulative earnings – related parties	0
Balance	$ 103,697

Property, Plant, and Equipmen_2

Property, Plant, and Equipment - Historical Cost Table (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	$ 12,689,438	$ 12,641,745
Less accumulated depreciation	4,049,900	3,931,800
Net property, plant, and equipment	8,639,538	8,709,945
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	9,741	9,696
Gathering Systems – Pipelines [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	$ 5,286,821	5,231,212
Estimated useful life	30 years
Gathering Systems – Compressors [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	$ 2,133,889	2,096,905
Estimated useful life	15 years
Processing Complexes And Treating Facilities [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	$ 3,434,442	3,424,368
Estimated useful life	25 years
Transportation Pipeline And Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	$ 168,205	168,205
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	$ 844,794	831,719
Estimated useful life	20 years
Assets Under Construction [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	$ 94,005	176,834
Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant, and equipment	$ 717,541	$ 702,806
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
	Mar. 31, 2021	Mar. 31, 2020
Property, Plant and Equipment [Line Items]
Long-lived asset and other impairments	$ 14,866	$ 155,785
DJ Basin Complex [Member]
Property, Plant and Equipment [Line Items]
Long-lived asset and other impairments	$ 13,500	10,700
Wyoming and Utah Assets [Member]
Property, Plant and Equipment [Line Items]
Long-lived asset and other impairments		145,100
Estimated salvage value		6,700
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		$ 91,000

Goodwill - Additional Informati

Goodwill - Additional Information (Details)	3 Months Ended
	Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)
Finite-Lived Intangible Assets [Line Items]
Number of reporting units	2
Goodwill impairment	$ 0	$ 441,017,000
Goodwill	$ 4,783,000		$ 4,783,000
Gathering and Processing Reporting Unit [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill		0
Transportation Reporting Unit [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill		$ 4,800,000

Selected Components of Workin_3

Selected Components of Working Capital - Accounts Receivable, Net Table (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Trade receivables, net	$ 480,265	$ 452,718
Other receivables, net	440	162
Total accounts receivable, net	480,705	452,880
WES Operating [Member]
Trade receivables, net	457,998	407,547
Other receivables, net	91	2
Total accounts receivable, net	$ 458,089	$ 407,549

Selected Components of Workin_4

Selected Components of Working Capital - Other Current Assets Table (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
NGLs inventory	$ 4,373	$ 882
Imbalance receivables	29,723	12,976
Prepaid insurance	6,741	8,131
Contract assets	14,745	5,338
Other	18,497	17,935
Total other current assets	74,079	45,262
WES Operating [Member]
NGLs inventory	4,373	882
Imbalance receivables	29,723	12,976
Prepaid insurance	5,150	6,113
Contract assets	14,745	5,338
Other	18,497	17,935
Total other current assets	$ 72,488	$ 43,244

Selected Components of Workin_5

Selected Components of Working Capital - Accrued Liabilities Table (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Accrued interest expense	$ 73,940	$ 137,307
Short-term asset retirement obligations	16,181	20,215
Short-term remediation and reclamation obligations	5,951	2,950
Income taxes payable	3,023	3,399
Contract liabilities	19,250	31,477
Other	81,840	74,599
Total accrued liabilities	200,185	269,947
Related Parties [Member]
Other	29,100
Total accrued liabilities	52,779	19,195
WES Operating [Member]
Accrued interest expense	73,940	137,307
Short-term asset retirement obligations	16,181	20,215
Short-term remediation and reclamation obligations	5,951	2,950
Income taxes payable	3,023	3,399
Contract liabilities	19,250	31,477
Other	55,818	35,485
Total accrued liabilities	$ 174,163	$ 230,833

Debt and Interest Expense - Deb

Debt and Interest Expense - Debt Outstanding Table (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Jan. 13, 2020
Debt Instrument [Line Items]
Total short-term debt, principal	$ 7,752	$ 439,345
Total short-term debt, carrying value	7,752	438,870
Long-term debt	7,416,001	7,415,832
Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Short-term debt, fair value	7,752	444,505
Long-Term Debt Obligations [Member]
Debt Instrument [Line Items]
Total long-term debt, principal	7,493,102	7,494,539
Long-term debt	7,416,001	7,415,832
Long-Term Debt Obligations [Member] | Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Long-term debt, fair value	7,818,095	7,845,524
WES Operating [Member]
Debt Instrument [Line Items]
Total short-term debt, carrying value	7,752	438,870
Long-term debt	7,416,001	7,415,832
WES Operating [Member] | Finance Lease Liability, Short Term [Member]
Debt Instrument [Line Items]
Finance leases - short-term debt	7,752	8,264
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	7,752	8,264
WES Operating [Member] | Finance Lease Liability, Long Term [Member]
Debt Instrument [Line Items]
Finance lease liabilities	22,207	23,644
WES Operating [Member] | Finance Lease Liability, Long Term [Member] | Valuation, Market Approach [Member] | Level-2 Inputs [Member]
Debt Instrument [Line Items]
Finance lease liabilities	$ 22,207	23,644
WES Operating [Member] | Senior Notes [Member] | 5.375% Senior Notes due 2021 [Member]
Debt Instrument [Line Items]
Senior note, interest rate	5.375%
Principal	$ 0	431,081
Short-term debt, carrying value	0	430,606
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	$ 0	436,241
WES Operating [Member] | Senior Notes [Member] | 4.000% Senior Notes due 2022 [Member]
Debt Instrument [Line Items]
Senior note, interest rate	4.00%
Principal	$ 580,917	580,917
Long-term debt, carrying value	580,613	580,555
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	596,358	597,568
WES Operating [Member] | Senior Notes [Member] | Floating-Rate Senior Notes due 2023 [Member]
Debt Instrument [Line Items]
Principal	239,978	239,978
Long-term debt, carrying value	239,013	238,879
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	$ 237,964	235,066
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	1,000,000
Long-term debt, carrying value	993,300	992,900
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	$ 1,035,754	1,028,614
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	500,000
Long-term debt, carrying value	495,132	494,866
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	$ 514,220	512,807
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	500,000
Long-term debt, carrying value	496,840	496,708
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	$ 527,584	524,880
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	400,000
Long-term debt, carrying value	395,746	395,617
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	$ 415,374	415,454
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	400,000
Long-term debt, carrying value	396,649	396,555
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	$ 418,284	418,786
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	1,200,000
Long-term debt, carrying value	1,189,637	1,189,407
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	$ 1,304,379	1,342,996
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	600,000
Long-term debt, carrying value	593,631	593,598
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	$ 617,579	607,234
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	700,000
Long-term debt, carrying value	687,101	687,048
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	$ 703,739	694,172
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	350,000
Long-term debt, carrying value	342,571	342,543
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	$ 342,609	343,928
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	1,000,000
Long-term debt, carrying value	983,561	983,512
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	$ 1,082,044	$ 1,100,375

Debt and Interest Expense - D_2

Debt and Interest Expense - Debt Activity Table (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Changes in Debt Outstanding [Roll Forward]
Beginning balance	$ 7,854,702
Other	2,081
Ending balance	7,423,753
WES Operating [Member] | RCF [Member] | Revolving Credit Facility [Member]
Changes in Debt Outstanding [Roll Forward]
Facility borrowings	100,000
Repayments of facility borrowings	(100,000)
WES Operating [Member] | Finance Lease Liability [Member]
Changes in Debt Outstanding [Roll Forward]
Changes in Finance Lease Obligations	(1,949)
WES Operating [Member] | 5.375% Senior Notes due 2021 [Member] | Senior Notes [Member]
Changes in Debt Outstanding [Roll Forward]
Repayments of senior notes	$ (431,081)
Senior note, interest rate	5.375%

Debt and Interest Expense - Int

Debt and Interest Expense - Interest Expense Table (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Debt Instrument [Line Items]
Interest expense	$ (98,493)	$ (88,586)
Third Parties [Member]
Debt Instrument [Line Items]
Interest on RCF and Senior Notes	(95,722)	(89,769)
Finance lease interest	(298)	(405)
Amortization of debt issuance costs and commitment fees	(3,338)	(3,127)
Capitalized interest	865	4,758
Interest expense	(98,493)	(88,543)
Related Parties [Member]
Debt Instrument [Line Items]
Finance lease interest	0	(43)
Interest expense	$ 0	$ (43)

Debt and Interest Expense - Add

Debt and Interest Expense - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Jan. 13, 2020
Debt Instrument [Line Items]
Gain (loss) on early extinguishment of debt	$ (289,000)	$ 7,345,000
WES Operating [Member]
Debt Instrument [Line Items]
Gain (loss) on early extinguishment of debt	(289,000)	$ 7,345,000
WES Operating [Member] | Third Parties [Member]
Debt Instrument [Line Items]
Future lease payments	$ 34,500,000
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%
Senior note, effective interest rate	4.542%	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%
Senior note, effective interest rate	5.424%	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%
Senior note, effective interest rate	6.629%	5.362%
WES Operating [Member] | Floating-Rate Senior Notes due 2023 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Senior note, effective interest rate	2.33%	2.69%
WES Operating [Member] | RCF [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility, expandable maximum borrowing capacity	$ 2,500,000,000
Facility, maximum borrowing capacity	2,000,000,000
Facility, outstanding borrowings	0
Facility, outstanding letters of credit	5,100,000
Facility, available borrowing capacity	$ 2,000,000,000
Facility, interest rate at period end	1.61%	2.13%
Facility, fee rate	0.25%	0.20%
Repayments of Lines of Credit	$ 100,000,000
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
WES Operating [Member] | Term Loan Facility [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Repayments of Lines of Credit		$ 3,000,000,000
Gain (loss) on early extinguishment of debt		$ (2,300,000)