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, 2019		3,345,293				3,209,947		(14,224)	149,570
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)		246,076
Balance at Sep. 30, 2020		2,790,456				2,674,682		(20,032)	135,806
Balance at Mar. 31, 2020		2,792,285				2,684,136		(24,990)	133,139
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)		281,341				267,576		5,461	8,304
Distributions to noncontrolling interest owners				(1,037)	(2,869)					(1,037)	(2,869)
Distributions to Partnership unitholders		(140,893)				(138,075)		(2,818)
Contributions of equity-based compensation from related parties			3,562				3,562
Equity-based compensation expense		2,115				2,115
Net contributions from (distributions to) related parties		1,343				1,343
Other		(330)				(330)
Balance at Jun. 30, 2020		2,935,517				2,820,327		(22,347)	137,537
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)		254,135				241,479		5,132	7,524
Distributions to noncontrolling interest owners				(1,148)	(2,869)					(1,148)	(2,869)
Distributions to Partnership unitholders		(140,900)				(138,083)		(2,817)
Unit exchange with Occidental	[2]				(261,878)	(256,640)					(5,238)
Contributions of equity-based compensation from related parties			3,488				3,488
Equity-based compensation expense		2,128				2,128
Net contributions from (distributions to) related parties		842				842
Other		1,141				1,141
Balance at Sep. 30, 2020		2,790,456				2,674,682		(20,032)	135,806
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	[3]	(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
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)		693,150
Balance at Sep. 30, 2021		3,096,446				2,965,944		(11,286)	141,788
Balance at Mar. 31, 2021		2,942,120				2,821,455		(16,033)	136,698
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)		238,277				226,295		4,964	7,018
Distributions to noncontrolling interest owners				(1,245)	(2,741)					(1,245)	(2,741)
Distributions to Partnership unitholders		(132,969)				(130,115)		(2,854)
Contributions of equity-based compensation from related parties			2,375				2,375
Equity-based compensation expense		4,746				4,746
Net contributions from (distributions to) related parties		2,881				2,881
Other		(571)				(571)
Balance at Jun. 30, 2021		3,052,873				2,927,066		(13,923)	139,730
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)		263,638				250,198		5,527	7,913
Distributions to noncontrolling interest owners				$ (1,213)	$ (4,642)					$ (1,213)	$ (4,642)
Distributions to Partnership unitholders		(134,662)				(131,772)		(2,890)
Unit repurchases	[3]	(88,125)				(88,125)
Contributions of equity-based compensation from related parties			$ 2,311				$ 2,311
Equity-based compensation expense		4,668				4,668
Net contributions from (distributions to) related parties		2,165				2,165
Other		(567)				(567)
Balance at Sep. 30, 2021		$ 3,096,446				$ 2,965,944		$ (11,286)	$ 141,788

[1] See Services Agreement within Note 6.

[2] See Note 6.

[3] See Note 5.