Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands		3 Months Ended						6 Months Ended			12 Months Ended
		Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018		Mar. 31, 2018	[1]	Jun. 30, 2019	Jun. 30, 2018		Dec. 31, 2018
Revenues and Other
Revenues and other		$ 685,054		$ 518,078	[1]			$ 1,356,937	$ 1,019,132	[1]
Equity income, net – affiliates		63,598		49,430	[1]			121,590	79,659	[1]
Operating expenses
Cost of product	[2]	122,877		95,656	[1]			236,940	189,974	[1]
Operation and maintenance	[2]	148,431		112,789	[1]			291,260	209,584	[1]
General and administrative	[2]	30,027		15,597	[1]			52,871	31,426	[1]
Property and other taxes		14,282		13,750	[1]			30,567	28,350	[1]
Depreciation and amortization		121,117		88,488	[1]			235,063	173,278	[1]
Impairments		797		127,184	[1]			1,187	127,384	[1]	$ 230,600
Total operating expenses		437,531		453,464	[1]			847,888	759,996	[1]
Gain (loss) on divestiture and other, net		(1,061)		170	[1]			(1,651)	286	[1]
Operating income (loss)		310,060		114,214	[1]			628,988	339,081	[1]
Interest income – affiliates		4,225		4,225	[1]			8,450	8,450	[1]
Interest expense	[3]	(79,472)		(42,245)	[1]			(145,348)	(80,260)	[1]
Other income (expense), net		(58,477)		1,277	[1]			(93,683)	2,094	[1]
Income (loss) before income taxes		176,336		77,471	[1]			398,407	269,365	[1]
Income tax expense (benefit)		1,278		10,304	[1]			11,370	21,188	[1]
Net income (loss)		175,058	$ 211,979	67,167	[1]	$ 181,010		387,037	248,177	[1]
Net income (loss) attributable to noncontrolling interests		5,464		(33,017)	[1]			98,783	16,466	[1]
Net income (loss) attributable to Western Midstream Partners, LP		169,594		100,184	[1]			288,254	231,711	[1]
Limited partners' interest in net income (loss):
Net income (loss) attributable to Western Midstream Partners, 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]
Affiliates [Member]
Revenues and Other
Revenues and other		385,184		289,544	[1]			763,621	574,720	[1]
Operating expenses
Cost of product		68,225		38,001				124,397	72,820
Operation and maintenance		32,318		26,826				71,459	49,827
General and administrative		26,892		12,262				45,786	24,950
Total operating expenses		127,435		77,089				241,642	147,597
Interest expense		(20)		(1,409)				(1,853)	(1,986)
Affiliates [Member] | Service Revenues - Fee Based [Member]
Revenues and Other
Revenues and other		343,484		234,512	[1]			670,126	456,550	[1]
Affiliates [Member] | Service Revenues - Product Based [Member]
Revenues and Other
Revenues and other		634		538	[1]			1,986	1,169	[1]
Affiliates [Member] | Product Sales [Member]
Revenues and Other
Revenues and other		41,066		54,494	[1]			91,509	117,001	[1]
Third Parties [Member]
Revenues and Other
Revenues and other		299,870		228,534	[1]			593,316	444,412	[1]
Operating expenses
Interest expense		(79,452)		(40,836)				(143,495)	(78,274)
Third Parties [Member] | Service Revenues - Fee Based [Member]
Revenues and Other
Revenues and other		250,060		197,349	[1]			503,392	369,084	[1]
Third Parties [Member] | Service Revenues - Product Based [Member]
Revenues and Other
Revenues and other		16,041		22,124	[1]			34,068	44,916	[1]
Third Parties [Member] | Product Sales [Member]
Revenues and Other
Revenues and other		33,403		8,821	[1]			55,093	29,939	[1]
Third Parties [Member] | Other [Member]
Revenues and Other
Revenues and other		$ 366		$ 240	[1]			$ 763	$ 473	[1]
Limited Partner [Member]
Limited partners' interest in net income (loss):
Net income (loss) per common unit - basic and diluted		$ 0.37		$ 0.31	[1]			$ 0.69	$ 0.77	[1]
Weighted-average common units outstanding - basic and diluted		453,000		218,934	[1]			376,702	218,934	[1]

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

[2] Cost of product includes product purchases from affiliates (as defined in Note 1) of $68.2 million and $124.4 million for the three and six months ended June 30, 2019, respectively, and $38.0 million and $72.8 million for the three and six months ended June 30, 2018, respectively. Operation and maintenance includes charges from affiliates of $32.3 million and $71.5 million for the three and six months ended June 30, 2019, respectively, and $26.8 million and $49.8 million for the three and six months ended June 30, 2018, respectively. General and administrative includes charges from affiliates of $26.9 million and $45.8 million for the three and six months ended June 30, 2019, respectively, and $12.3 million and $25.0 million for the three and six months ended June 30, 2018, respectively. See Note 6.

[3] Includes affiliate (as defined in Note 1) amounts of $0.02 million and $1.9 million for the three and six months ended June 30, 2019, respectively, and $1.4 million and $2.0 million for the three and six months ended June 30, 2018, respectively. See Note 1 and Note 10.