Transactions with Affiliates - Purchases Table (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017
Related Party Transaction [Line Items]
Partners’ capital adjustment	$ 0	$ (1,373)
Western Gas Partners, LP [Member] \| Affiliates [Member]
Related Party Transaction [Line Items]
Cash consideration	254	3,910
Net carrying value	(254)	(5,283)
Partners’ capital adjustment	$ 0	$ (1,373)

The cash outflow to purchase long lived physical asset for use in the normal oil and gas operations and to purchase mineral interests in oil and gas properties not intended for resale.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (c)
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Amount of increase (decrease) of physical assets used in the normal conduct of business and not intended for resale, from reclassification, impairment, donation, or changes classified as other. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
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Total change in each class of partners' capital accounts during the year due to distributions to or contributions from affiliates of other assets.

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