The number of general partner units outstanding.

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- Definition

The number of limited partner units outstanding.

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- Definition

The number of units converted into shares of each class of partners' capital account. Units represent shares of ownership of the general, limited, and preferred partners.

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- Definition

The number of units sold in a private placement of each class of partners' capital account. Units represent shares of ownership of the general, limited, and preferred partners.

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- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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- Definition

The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

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Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

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No definition available.

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Subsequent Events - Additional Information (Details) - USD ($) $ in Thousands		12 Months Ended
	Feb. 28, 2019	Dec. 31, 2018	Dec. 31, 2017
Subsequent Event [Line Items]
Acquisitions		$ 162,615	$ 22,500
Common units outstanding		218,937,797	218,933,141
Western Gas Equity Partners, LP [Member] \| Common Units [Member] \| Scenario, Forecast [Member]
Subsequent Event [Line Items]
Conversion of units	55,360,984
Western Gas Equity Partners, LP [Member] \| Western Gas Partners, LP [Member]
Subsequent Event [Line Items]
General partner units owned		2,583,068
Western Gas Equity Partners, LP [Member] \| Western Gas Partners, LP [Member] \| Scenario, Forecast [Member]
Subsequent Event [Line Items]
General partner units owned	2,583,068
Western Gas Equity Partners, LP [Member] \| Western Gas Partners, LP [Member] \| Common Units [Member]
Subsequent Event [Line Items]
Common units outstanding		50,132,046
Anadarko [Member] \| Western Gas Partners, LP [Member] \| Common Units [Member] \| Scenario, Forecast [Member]
Subsequent Event [Line Items]
Common units outstanding	6,375,284
Western Gas Partners, LP [Member]
Subsequent Event [Line Items]
Units issued		1,128,782	885,760
Conversion of units			0
Western Gas Partners, LP [Member] \| Anadarko [Member] \| Anadarko Midstream Assets [Member] \| Scenario, Forecast [Member]
Subsequent Event [Line Items]
Cash payment for acquisition	$ 1,814,000
Acquisitions	$ 193,900
Western Gas Partners, LP [Member] \| Class C Units [Member]
Subsequent Event [Line Items]
Units issued		1,128,782	885,760
Western Gas Partners, LP [Member] \| Class C Units [Member] \| Scenario, Forecast [Member]
Subsequent Event [Line Items]
Conversion of units	1
Western Gas Partners, LP [Member] \| Common Units [Member]
Subsequent Event [Line Items]
Conversion of units			21,922,831
Western Gas Partners, LP [Member] \| Common Units [Member] \| Scenario, Forecast [Member]
Subsequent Event [Line Items]
Conversion of units	105,624,704
Western Gas Partners, LP [Member] \| Common Units [Member] \| Anadarko [Member] \| Anadarko Midstream Assets [Member] \| Scenario, Forecast [Member]
Subsequent Event [Line Items]
Units issued	45,760,201