Equity and Partners' Capital - Calculation of WES Operating Net Income (Loss) Per Unit Table (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended			6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018		Jun. 30, 2019	Jun. 30, 2018
Earnings Per Unit [Line Items]
Net income (loss) attributable to Western Midstream Operating, LP		$ 169,594	$ 100,184	[1]	$ 288,254	$ 231,711	[1]
Pre-acquisition net (income) loss allocated to Anadarko		(163)	(32,604)	[1]	(29,279)	(63,126)	[1]
Limited partners' interest in net income (loss)		169,431	67,580	[1]	258,975	168,585	[1]
WES Operating [Member]
Earnings Per Unit [Line Items]
Net income (loss) attributable to Western Midstream Operating, LP		175,012	65,312	[1]	387,608	245,197	[1]
Pre-acquisition net (income) loss allocated to Anadarko		(163)	(32,604)	[1]	(29,279)	(63,126)	[1]
General partner interest in net (income) loss	[2]	$ 0	(84,176)	[1]	$ 0	(167,615)	[1]
WES Operating [Member] | Common and Class C Units [Member]
Earnings Per Unit [Line Items]
Limited partners' interest in net income (loss)			(51,468)			14,456
WES Operating [Member] | Common Units [Member]
Earnings Per Unit [Line Items]
Limited partners' interest in net income (loss)			$ (48,417)			$ 9,906
Net income (loss) per common unit - basic and diluted	[1],[2]		$ (0.32)			$ 0.06
Weighted-average common units outstanding - basic and diluted			152,604			152,603
WES Operating [Member] | Class C Units [Member]
Earnings Per Unit [Line Items]
Limited partners' interest in net income (loss)			$ (3,051)			$ 4,550
Anti-dilutive units excluded from computation of earnings per unit			13,649			13,516

[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 5 for the calculation of net income (loss) per common unit.