Equity and Partners' Capital - Calculation of WES Operating Net Income (Loss) Per Unit Table (Details) - USD ($) $ / shares in Units, $ in Thousands				12 Months Ended
		May 02, 2017	Mar. 01, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Unit [Line Items]
Net income (loss) attributable to Western Midstream Operating, LP				$ 697,241	$ 551,571	$ 540,790
Pre-acquisition net (income) loss allocated to Anadarko				(29,279)	(182,142)	(164,183)
General partner interest in net (income) loss				(5,637)	0	0
Limited partners' interest in net income (loss)	[1]			662,325	369,429	376,607
WES Operating [Member]
Earnings Per Unit [Line Items]
Net income (loss) attributable to Western Midstream Operating, LP				807,590	627,917	731,666
Pre-acquisition net (income) loss allocated to Anadarko				(29,279)	(182,142)	(164,183)
General partner interest in net (income) loss	[2]			0	(346,538)	(303,835)
WES Operating [Member] | Series A Preferred Units [Member]
Earnings Per Unit [Line Items]
Limited partners' interest in net income (loss)	[2]			$ 0	$ 0	$ 42,373
Anti-dilutive units excluded from computation of earnings per unit					0	5,406,000
WES Operating [Member] | Series A Preferred Units [Member] | Series A Preferred Units March 2017 Conversion [Member]
Earnings Per Unit [Line Items]
Series A Preferred units, percentage converted			50.00%
Series A Preferred units, common units issued upon conversion			1
WES Operating [Member] | Series A Preferred Units [Member] | Series A Preferred Units May 2017 Conversion [Member]
Earnings Per Unit [Line Items]
Series A Preferred units, percentage converted		50.00%
Series A Preferred units, common units issued upon conversion		1
WES Operating [Member] | Common and Class C Units [Member]
Earnings Per Unit [Line Items]
Limited partners' interest in net income (loss)					$ 99,237	$ 221,275
WES Operating [Member] | Common Units [Member]
Earnings Per Unit [Line Items]
Limited partners' interest in net income (loss)					$ 84,334	$ 192,066
Net income (loss) per common unit - basic and diluted	[2]				$ 0.55	$ 1.30
Weighted-average common units outstanding - basic and diluted					152,606,000	147,194,000
WES Operating [Member] | Class C Units [Member]
Earnings Per Unit [Line Items]
Limited partners' interest in net income (loss)					$ 14,903	$ 29,209
Anti-dilutive units excluded from computation of earnings per unit					13,795,000	12,776,000

[1] See Note 1.

[2] See Note 5 for the calculation of net income (loss) per common unit.