Operating Segments (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) segment	Jun. 30, 2014 USD ($)
Operating Segments
Operating segments number | segment			3
Revenues:
Revenues	$ 6,663	$ 11,195	$ 12,605	$ 22,878
Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments
Equity earnings in unconsolidated entities	52	23	89	44
Segment profit	371	488	884	1,097
Maintenance capital	52	48	102	95
Transportation
Revenues:
Revenues	180	195	366	376
Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments
Equity earnings in unconsolidated entities	52	23	89	44
Segment profit	186	221	428	427
Maintenance capital	33	42	66	76
Facilities
Revenues:
Revenues	137	144	261	301
Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments
Segment profit	144	134	285	288
Maintenance capital	17	5	32	15
Supply and Logistics
Revenues:
Revenues	6,346	10,856	11,978	22,201
Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments
Segment profit	41	133	171	382
Maintenance capital	2	1	4	4
Interest expense related to hedged inventory purchases	2	5	3	7
Operating Segments
Revenues:
Revenues	7,022	11,549	13,312	23,602
Operating Segments | Transportation
Revenues:
Revenues	402	412	803	798
Operating Segments | Facilities
Revenues:
Revenues	269	277	525	576
Operating Segments | Supply and Logistics
Revenues:
Revenues	6,351	10,860	11,984	22,228
Intersegment
Revenues:
Revenues	(359)	(354)	(707)	(724)
Intersegment | Transportation
Revenues:
Revenues	(222)	(217)	(437)	(422)
Intersegment | Facilities
Revenues:
Revenues	(132)	(133)	(264)	(275)
Intersegment | Supply and Logistics
Revenues:
Revenues	$ (5)	$ (4)	$ (6)	$ (27)