Operating Segments - Segment Financial Data (Details) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2020 USD ($) segment	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Operating Segments
Operating segments number | segment									3
Revenues:
Revenues	$ 5,963	$ 5,833	$ 3,225	$ 8,269	$ 9,154	$ 7,886	$ 8,253	$ 8,375	$ 23,290	$ 33,669	$ 34,055
Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments
Equity earnings in unconsolidated entities									355	388	375
Segment Adjusted EBITDA									2,557	3,230	2,681
Investment and acquisition capital									1,231	1,387	1,888
Maintenance capital									216	287	252
Total assets	24,497				28,677				24,497	28,677	25,511
Investments in unconsolidated entities	3,764				3,683				3,764	3,683	2,702
Transportation
Revenues:
Revenues									610	788	648
Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments
Equity earnings in unconsolidated entities									350	388	375
Segment Adjusted EBITDA									1,616	1,722	1,508
Investment and acquisition capital									981	1,127	1,631
Maintenance capital									136	161	139
Total assets	13,631				14,902				13,631	14,902	13,288
Investments in unconsolidated entities	3,642				3,557				3,642	3,557	2,594
Facilities
Revenues:
Revenues									622	609	588
Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments
Equity earnings in unconsolidated entities									5
Segment Adjusted EBITDA									731	705	711
Investment and acquisition capital									173	227	234
Maintenance capital									51	97	100
Total assets	5,845				7,336				5,845	7,336	7,200
Investments in unconsolidated entities	122				126				122	126	108
Supply and Logistics
Revenues:
Revenues									22,058	32,272	32,819
Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments
Segment Adjusted EBITDA									210	803	462
Investment and acquisition capital									77	33	23
Maintenance capital									29	29	13
Total assets	5,021				6,439				5,021	6,439	5,023
Investments in unconsolidated entities	$ 0				$ 0				0	0	0
Operating Segments Excluding Intersegment Elimination | Transportation
Revenues:
Revenues									1,016	1,259	1,116
Operating Segments Excluding Intersegment Elimination | Facilities
Revenues:
Revenues									622	609	588
Operating Segments Excluding Intersegment Elimination | Supply and Logistics
Revenues:
Revenues									22,058	32,272	32,819
Intersegment
Revenues:
Revenues									(1,927)	(2,098)	(1,918)
Intersegment | Transportation
Revenues:
Revenues									(1,004)	(1,061)	(874)
Intersegment | Facilities
Revenues:
Revenues									(516)	(562)	(573)
Intersegment | Supply and Logistics
Revenues:
Revenues									(1)	(4)	(3)
Intersegment Adjustment
Revenues:
Revenues									(406)	(471)	(468)
Operating Segments
Revenues:
Revenues									25,217	35,767	35,973
Operating Segments | Transportation
Revenues:
Revenues									2,020	2,320	1,990
Operating Segments | Facilities
Revenues:
Revenues									1,138	1,171	1,161
Operating Segments | Supply and Logistics
Revenues:
Revenues									$ 22,059	$ 32,276	$ 32,822