Debt and Interest Expense - Debt Activity Table (Details) $ in Thousands	6 Months Ended
Jun. 30, 2015 USD ($)
Debt Instrument [Line Items]
Beginning balance	$ 2,424,104
Ending balance	2,677,023
Working Capital Facility [Member] \| Anadarko [Member]
Debt Instrument [Line Items]
Repayments	(1,150)
Western Gas Partners, LP [Member]
Debt Instrument [Line Items]
Other	(5,931)
Western Gas Partners, LP [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Borrowings	280,000
Repayments	(520,000)
Western Gas Partners, LP [Member] \| Senior Notes [Member] \| 3.950% Senior Notes due 2025 [Member]
Debt Instrument [Line Items]
Issuance of Senior Notes	$ 500,000

Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-Section S99
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6513228

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