Goodwill and Intangibles (Intangible Assets) (Details) - USD ($) $ in Millions			12 Months Ended
		Oct. 01, 2018	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross			$ 1,571	$ 1,502
Accumulated amortization	[1]		(301)	(143)
Intangibles, net			1,270	1,359
Logistics and Storage [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets			31	14
Gross			283	249
Accumulated amortization	[1]		(45)	(14)
Intangibles, net			$ 238	235
Logistics and Storage [Member] | Minimum
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life			6 years
Logistics and Storage [Member] | Maximum
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life			8 years
Gathering and Processing [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets			$ 127	49
Gross			1,288	1,253
Accumulated amortization	[1]		(256)	(129)
Intangibles, net			$ 1,032	$ 1,124
Gathering and Processing [Member] | Minimum
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life			6 years
Gathering and Processing [Member] | Maximum
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life			25 years
Andeavor Logistics [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life			9 years
Andeavor Logistics [Member] | Minimum
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life		2 years
Andeavor Logistics [Member] | Maximum
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life		10 years

[1] Amortization expense attributable to the G&P segment for the years ended December 31, 2019 and 2018 was $127 million and $49 million, respectively. Amortization expense attributable to the L&S segment for the year ended December 31, 2019 and 2018 was $31 million and $14 million, respectively.