Operating Segments - Segment Financial Data (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) segment	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Segment Reporting Information [Line Items]
Operating segments number | segment			3
Revenues:
Revenues	$ 5,833	$ 7,886	$ 17,327	$ 24,515
Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments
Equity earnings in unconsolidated entities	89	102	280	274
Segment Adjusted EBITDA	681	727	1,998	2,371
Maintenance capital	53	85	157	204
Total assets	25,693		25,693		$ 29,969
Transportation
Revenues:
Revenues	146	196	484	581
Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments
Equity earnings in unconsolidated entities	87	102	276	274
Segment Adjusted EBITDA	444	462	1,233	1,271
Maintenance capital	34	42	98	110
Total assets	14,486		14,486		15,549
Facilities
Revenues:
Revenues	150	149	473	457
Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments
Equity earnings in unconsolidated entities	2		4
Segment Adjusted EBITDA	176	173	560	529
Maintenance capital	10	28	40	74
Total assets	6,331		6,331		7,593
Supply and Logistics
Revenues:
Revenues	5,537	7,541	16,370	23,477
Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments
Segment Adjusted EBITDA	61	92	205	571
Maintenance capital	9	15	19	20
Total assets	4,876		4,876		$ 6,827
Operating Segments Excluding Intersegment Elimination | Transportation
Revenues:
Revenues	242	319	774	938
Operating Segments Excluding Intersegment Elimination | Facilities
Revenues:
Revenues	150	149	473	457
Operating Segments Excluding Intersegment Elimination | Supply and Logistics
Revenues:
Revenues	5,537	7,541	16,370	23,477
Intersegment
Revenues:
Revenues	(469)	(544)	(1,434)	(1,557)
Intersegment | Transportation
Revenues:
Revenues	(252)	(278)	(756)	(774)
Intersegment | Facilities
Revenues:
Revenues	(121)	(142)	(387)	(423)
Intersegment | Supply and Logistics
Revenues:
Revenues		(1)	(1)	(3)
Intersegment Adjustment
Revenues:
Revenues	(96)	(123)	(290)	(357)
Operating Segments
Revenues:
Revenues	6,302	8,430	18,761	26,072
Operating Segments | Transportation
Revenues:
Revenues	494	597	1,530	1,712
Operating Segments | Facilities
Revenues:
Revenues	271	291	860	880
Operating Segments | Supply and Logistics
Revenues:
Revenues	$ 5,537	$ 7,542	$ 16,371	$ 23,480