Transactions with Affiliates - Commodity Price Swap Agreements Extensions Tables (Details) - Western Gas Partners, LP [Member]		Dec. 01, 2016 $ / MMBTU $ / bbl	Dec. 31, 2015 $ / MMBTU $ / bbl	Dec. 08, 2015 $ / MMBTU $ / bbl	Jun. 25, 2015 $ / MMBTU $ / bbl
DJ Basin Complex [Member] | Years 2015 - 2017 [Member] | Ethane [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price					18.41
DJ Basin Complex [Member] | Years 2015 - 2017 [Member] | Propane [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price					47.08
DJ Basin Complex [Member] | Years 2015 - 2017 [Member] | Isobutane [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price					62.09
DJ Basin Complex [Member] | Years 2015 - 2017 [Member] | Normal butane [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price					54.62
DJ Basin Complex [Member] | Years 2015 - 2017 [Member] | Natural gasoline [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price					72.88
DJ Basin Complex [Member] | Years 2015 - 2017 [Member] | Condensate [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price					76.47
DJ Basin Complex [Member] | Years 2015 - 2017 [Member] | Natural gas (per MMBtu) [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price | $ / MMBTU					5.96
DJ Basin Complex [Member] | Year 2015 [Member] | Ethane [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]				1.96
DJ Basin Complex [Member] | Year 2015 [Member] | Propane [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]				13.10
DJ Basin Complex [Member] | Year 2015 [Member] | Isobutane [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]				19.75
DJ Basin Complex [Member] | Year 2015 [Member] | Normal butane [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]				18.99
DJ Basin Complex [Member] | Year 2015 [Member] | Natural gasoline [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]				52.59
DJ Basin Complex [Member] | Year 2015 [Member] | Condensate [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]				52.59
DJ Basin Complex [Member] | Year 2015 [Member] | Natural gas (per MMBtu) [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price | $ / MMBTU	[1]				2.75
DJ Basin Complex [Member] | Year 2016 [Member] | Ethane [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]			0.60
DJ Basin Complex [Member] | Year 2016 [Member] | Propane [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]			10.98
DJ Basin Complex [Member] | Year 2016 [Member] | Isobutane [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]			17.23
DJ Basin Complex [Member] | Year 2016 [Member] | Normal butane [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]			16.86
DJ Basin Complex [Member] | Year 2016 [Member] | Natural gasoline [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]			26.15
DJ Basin Complex [Member] | Year 2016 [Member] | Condensate [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]			34.65
DJ Basin Complex [Member] | Year 2016 [Member] | Natural gas (per MMBtu) [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price | $ / MMBTU	[1]			2.11
DJ Basin Complex [Member] | Year 2017 [Member] | Ethane [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]	5.09
DJ Basin Complex [Member] | Year 2017 [Member] | Propane [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]	18.85
DJ Basin Complex [Member] | Year 2017 [Member] | Isobutane [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]	26.83
DJ Basin Complex [Member] | Year 2017 [Member] | Normal butane [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]	26.20
DJ Basin Complex [Member] | Year 2017 [Member] | Natural gasoline [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]	41.84
DJ Basin Complex [Member] | Year 2017 [Member] | Condensate [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]	45.40
DJ Basin Complex [Member] | Year 2017 [Member] | Natural gas (per MMBtu) [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price | $ / MMBTU	[1]	3.05
Hugoton System [Member] | Year 2015 [Member] | Condensate [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1],[2]				32.56
Hugoton System [Member] | Year 2015 [Member] | Natural gas (per MMBtu) [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price | $ / MMBTU	[1],[2]				2.74
Hugoton System [Member] | Year 2016 [Member] | Condensate [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1],[2]			18.81
Hugoton System [Member] | Year 2016 [Member] | Natural gas (per MMBtu) [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price | $ / MMBTU	[1],[2]			2.12
Hugoton System [Member] | Years 2015 - 2016 [Member] | Condensate [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price	[2]				78.61
Hugoton System [Member] | Years 2015 - 2016 [Member] | Natural gas (per MMBtu) [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price | $ / MMBTU	[2]				5.50
MGR Assets [Member] | Year 2015 [Member] | Ethane [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price			23.41
MGR Assets [Member] | Year 2015 [Member] | Propane [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price			52.99
MGR Assets [Member] | Year 2015 [Member] | Isobutane [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price			74.02
MGR Assets [Member] | Year 2015 [Member] | Normal butane [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price			65.04
MGR Assets [Member] | Year 2015 [Member] | Natural gasoline [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price			81.82
MGR Assets [Member] | Year 2015 [Member] | Condensate [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price			81.82
MGR Assets [Member] | Year 2015 [Member] | Natural gas (per MMBtu) [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price | $ / MMBTU			4.66
MGR Assets [Member] | Year 2017 [Member] | Ethane [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]	4.08
MGR Assets [Member] | Year 2017 [Member] | Propane [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]	19.24
MGR Assets [Member] | Year 2017 [Member] | Isobutane [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]	25.79
MGR Assets [Member] | Year 2017 [Member] | Normal butane [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]	25.16
MGR Assets [Member] | Year 2017 [Member] | Natural gasoline [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]	45.01
MGR Assets [Member] | Year 2017 [Member] | Condensate [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price	[1]	53.55
MGR Assets [Member] | Year 2017 [Member] | Natural gas (per MMBtu) [Member]
Commodity Price Risk Swap [Line Items]
Commodity market price | $ / MMBTU	[1]	3.05
MGR Assets [Member] | Years 2016 - 2017 [Member] | Ethane [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price		23.11
MGR Assets [Member] | Years 2016 - 2017 [Member] | Propane [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price		52.90
MGR Assets [Member] | Years 2016 - 2017 [Member] | Isobutane [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price		73.89
MGR Assets [Member] | Years 2016 - 2017 [Member] | Normal butane [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price		64.93
MGR Assets [Member] | Years 2016 - 2017 [Member] | Natural gasoline [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price		81.68
MGR Assets [Member] | Years 2016 - 2017 [Member] | Condensate [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price		81.68
MGR Assets [Member] | Years 2016 - 2017 [Member] | Natural gas (per MMBtu) [Member]
Commodity Price Risk Swap [Line Items]
Commodity swap fixed price | $ / MMBTU		4.87

[1] Represents the New York Mercantile Exchange forward strip price as of June 25, 2015, December 8, 2015 and December 1, 2016, for the 2015 Market Prices, 2016 Market Prices and 2017 Market Prices, respectively, adjusted for product specification, location, basis and, in the case of NGLs, transportation and fractionation costs.

[2] The Hugoton system was sold in October 2016. See Note 2.