Consolidated Statements of Equity and Partners' Capital - USD ($) $ in Thousands		Total	Chipeta [Member]	WES Operating [Member]	Net Investment by Anadarko [Member]	Common Units [Member]	Noncontrolling Interests [Member]	Noncontrolling Interests [Member] Chipeta [Member]	Noncontrolling Interests [Member] WES Operating [Member]
Balance at Dec. 31, 2017	[1]	$ 4,995,050			$ 1,050,171	$ 1,061,125	$ 2,883,754
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)	[1]	181,010			30,522	101,005	49,483
Above-market component of swap agreements with Anadarko	[1],[2]	14,282				14,282
WES Operating equity transactions, net	[1],[3]	0				(2,525)	2,525
Distributions to noncontrolling interest owners	[1]		$ (3,353)	$ (94,272)				$ (3,353)	$ (94,272)
Distributions to Partnership unitholders	[1]	(120,140)				(120,140)
Contributions of equity-based compensation from Anadarko	[1]	1,470				1,470
Net pre-acquisition contributions from (distributions to) Anadarko	[1]	64,251			64,251
Adjustments of net deferred tax liabilities	[1]	(175)			(175)
Other	[1]	150				58	92
Balance at Mar. 31, 2018	[1]	4,994,493			1,145,398	1,041,066	2,808,029
Increase (Decrease) in Partners' Capital [Roll Forward]
Cumulative effect of accounting change	[1]	(43,780)			629	(14,209)	(30,200)
Balance at Dec. 31, 2018	[1]	4,892,683			1,388,018	951,888	2,552,777
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income (loss)		211,979			29,116	89,544	93,319
Cumulative impact of the Merger transactions	[4]	0				3,169,800	(3,169,800)
Above-market component of swap agreements with Anadarko	[5]	7,407				7,407
WES Operating equity transactions, net	[6]	0				(752,796)	752,796
Distributions to noncontrolling interest owners			$ (1,935)	$ (100,999)				$ (1,935)	$ (100,999)
Distributions to Partnership unitholders		(131,910)				(131,910)
Acquisitions from affiliates	[7]	(2,007,501)			(2,141,827)	106,856	27,470
Contributions of equity-based compensation from Anadarko		1,840				1,840
Net pre-acquisition contributions from (distributions to) Anadarko		451,591			451,591
Adjustments of net deferred tax liabilities		268,727			273,102	(4,375)
Other		(341)				(332)	(9)
Balance at Mar. 31, 2019		$ 3,591,541			$ 0	$ 3,437,922	$ 153,619

[1] Financial information has been recast to include the financial position and results attributable to AMA. See Note 1 and Note 3.

[2] See Note 6.

[3] The $2.5 million decrease to partners’ capital, together with net income (loss) attributable to Western Midstream Partners, LP, totaled $129.0 million for the three months ended March 31, 2018.

[4] See Note 1.

[5] See Note 6.

[6] The $752.8 million decrease to partners’ capital, together with net income (loss) attributable to Western Midstream Partners, LP, totaled $(634.1) million for the three months ended March 31, 2019.

[7] The amounts allocated to common unitholders and noncontrolling interests represent a noncash investing activity related to the assets and liabilities assumed in the AMA acquisition.