Operating Segments - Segment Financial Data (Details) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2018 USD ($) segment	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Operating Segments
Operating segments number | segment									3
Revenues:
Revenues	$ 8,786	$ 8,792	$ 8,080	$ 8,398	$ 7,605	$ 5,873	$ 6,078	$ 6,667	$ 34,055	$ 26,223	$ 20,182
Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments
Equity earnings in unconsolidated entities									375	290	195
Segment Adjusted EBITDA									2,681	2,081	2,167
Capital expenditures									1,888	2,458	1,694
Maintenance capital									252	247	186
Total assets	25,511				25,351				25,511	25,351	24,210
Investments in unconsolidated entities	2,702				2,756				2,702	2,756	2,343
Transportation
Revenues:
Revenues									1,116	1,021	954
Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments
Equity earnings in unconsolidated entities									375	290	195
Segment Adjusted EBITDA									1,508	1,287	1,141
Capital expenditures									1,631	2,126	1,063
Maintenance capital									139	120	121
Total assets	13,288				12,661				13,288	12,661	10,917
Investments in unconsolidated entities	2,594				2,681				2,594	2,681	2,290
Facilities
Revenues:
Revenues									588	555	546
Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments
Segment Adjusted EBITDA									711	734	667
Capital expenditures									234	312	577
Maintenance capital									100	114	55
Total assets	7,200				7,313				7,200	7,313	7,556
Investments in unconsolidated entities	108				75				108	75	53
Supply and Logistics
Revenues:
Revenues									32,819	25,056	19,004
Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments
Segment Adjusted EBITDA									462	60	359
Capital expenditures									23	20	54
Maintenance capital									13	13	10
Total assets	5,023				5,377				5,023	5,377	5,737
Investments in unconsolidated entities	$ 0				$ 0				0	0	0
Operating Segments
Revenues:
Revenues									35,973	27,956	21,709
Operating Segments | Transportation
Revenues:
Revenues									1,990	1,718	1,584
Operating Segments | Facilities
Revenues:
Revenues									1,161	1,173	1,107
Operating Segments | Supply and Logistics
Revenues:
Revenues									32,822	25,065	19,018
Intersegment
Revenues:
Revenues									(1,918)	(1,733)	(1,527)
Intersegment | Transportation
Revenues:
Revenues									(874)	(697)	(630)
Intersegment | Facilities
Revenues:
Revenues									(573)	(618)	(561)
Intersegment | Supply and Logistics
Revenues:
Revenues									(3)	(9)	(14)
Intersegment Adjustment
Revenues:
Revenues									$ (468)	$ (409)	$ (322)