Equity and Partners' Capital - Additional Information (Details) $ / shares in Units, $ in Thousands		1 Months Ended				3 Months Ended		9 Months Ended			12 Months Ended
	Mar. 14, 2016 USD ($) $ / shares shares	Jun. 30, 2016 shares	Apr. 30, 2016 USD ($) shares	Jun. 30, 2015 $ / unit shares	Nov. 30, 2014 USD ($) $ / shares shares	Jun. 30, 2016 shares	Mar. 31, 2016 shares	Sep. 30, 2016 USD ($) $ / shares shares	Sep. 30, 2015 USD ($)	[1]	Dec. 31, 2015 USD ($) $ / shares shares	Aug. 31, 2014 USD ($)
Schedule of Investments [Line Items]
Limited partner units owned								218,922,303			218,919,380
Anadarko [Member]
Schedule of Investments [Line Items]
Limited partner units owned								178,587,365
Ownership interest								81.60%
Anadarko [Member] | 7.50% Tangible Equity Units [Member]
Schedule of Investments [Line Items]
Tangible equity units issued				9,200,000
Tangible equity unit rate				7.50%
Stated amount per tangible equity unit | $ / unit				50.00
Debt instrument, maturity date				Jun. 07, 2018
Anadarko [Member] | 7.50% Tangible Equity Units [Member] | Over-Allotment Option [Member]
Schedule of Investments [Line Items]
Tangible equity units issued				1,200,000
Anadarko [Member] | Common Units [Member]
Schedule of Investments [Line Items]
Common units issued		12,500,000		2,300,000
Anadarko [Member] | Common Units [Member] | Over-Allotment Option [Member]
Schedule of Investments [Line Items]
Common units issued				300,000
Public [Member]
Schedule of Investments [Line Items]
Limited partner units owned								40,334,938
Ownership interest								18.40%
Western Gas Partners, LP [Member]
Schedule of Investments [Line Items]
General partner units owned								2,583,068
General partner's interest								1.50%
Units issued								748,562
Western Gas Partners, LP [Member] | 500 Million COP [Member]
Schedule of Investments [Line Items]
Maximum aggregate principal of common units | $												$ 500,000
Average price per unit | $ / shares											$ 66.61
Net proceeds to WES | $											$ 57,400
Underwriting discount and other offering expenses | $											800
Gross proceeds | $											58,200
Commissions paid | $											$ 600
Western Gas Partners, LP [Member] | Class C Units [Member]
Schedule of Investments [Line Items]
Units issued								748,562
Price per unit | $ / shares					$ 68.72
Proceeds from the issuance of WES units | $					$ 750,000
Western Gas Partners, LP [Member] | Class C Units [Member] | Maximum [Member]
Schedule of Investments [Line Items]
Redeemable option on units | $					$ 150,000
Western Gas Partners, LP [Member] | Series A Preferred Units [Member]
Schedule of Investments [Line Items]
Price per unit | $ / shares	$ 32.00
Proceeds from the issuance of WES units | $	$ 440,000							$ 686,937	$ 0
Transaction fee	2.00%
Series A Preferred units, units issued upon conversion								1
Minimum common unit closing price for conversion | $ / shares								$ 48.00
Western Gas Partners, LP [Member] | Series A Preferred Units [Member] | Over-Allotment Option [Member]
Schedule of Investments [Line Items]
Proceeds from the issuance of WES units | $			$ 246,900
Western Gas Partners, LP [Member] | Common Units [Member]
Schedule of Investments [Line Items]
Limited partner units owned								50,132,046
Ownership interest								30.00%
Western Gas Partners, LP [Member] | Common Units [Member] | 500 Million COP [Member]
Schedule of Investments [Line Items]
Common units issued								0			873,525
Western Gas Partners, LP [Member] | Incentive Distribution Rights [Member]
Schedule of Investments [Line Items]
General partner's interest								100.00%
Western Gas Partners, LP [Member] | Private Investor [Member] | Over-Allotment Option [Member]
Schedule of Investments [Line Items]
Units issued								7,892,220
Western Gas Partners, LP [Member] | Private Investor [Member] | Series A Preferred Units [Member]
Schedule of Investments [Line Items]
Limited partner units owned								21,922,831
Ownership interest								13.10%
Units issued	14,030,611						14,030,611
Western Gas Partners, LP [Member] | Private Investor [Member] | Series A Preferred Units [Member] | Over-Allotment Option [Member]
Schedule of Investments [Line Items]
Units issued			7,892,220			7,892,220		7,892,220
Western Gas Partners, LP [Member] | Public [Member] | Common Units [Member]
Schedule of Investments [Line Items]
Limited partner units owned								78,528,544
Ownership interest								46.90%
Western Gas Partners, LP [Member] | Other Subsidiaries Of Anadarko [Member] | Class C Units [Member]
Schedule of Investments [Line Items]
Limited partner units owned								12,160,424
Units issued					10,913,853
Western Gas Partners, LP [Member] | Other Subsidiaries Of Anadarko [Member] | Common Units [Member]
Schedule of Investments [Line Items]
Limited partner units owned								2,011,380
Western Gas Partners, LP [Member] | Other Subsidiaries Of Anadarko [Member] | Common and Class C Units [Member]
Schedule of Investments [Line Items]
Ownership interest								8.50%
Western Gas Partners, LP [Member] | Change In Control [Member] | Series A Preferred Units [Member]
Schedule of Investments [Line Items]
Redemption price per unit | $ / shares								$ 32.32

[1] Financial information has been recast to include the financial position and results attributable to the Springfield interest. See Note 1 and Note 2.