Operating Segments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 segment	Sep. 30, 2012
Operating Segments
Operating segments number			3
Revenues:
External Customers	$ 10,703	$ 9,354	$ 31,617	$ 28,358
Intersegment	341	321	1,021	838
Total revenues of reportable segments	11,044	9,675	32,638	29,196
Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments
Equity earnings in unconsolidated entities	19	9	42	25
Segment profit	408	466	1,640	1,404
Maintenance capital	42	47	124	123
Transportation
Revenues:
External Customers	179	150	517	458
Intersegment	199	214	594	585
Total revenues of reportable segments	378	364	1,111	1,043
Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments
Equity earnings in unconsolidated entities	19	9	42	25
Segment profit	198	184	522	516
Maintenance capital	29	26	84	78
Facilities
Revenues:
External Customers	138	156	558	533
Intersegment	142	106	425	252
Total revenues of reportable segments	280	262	983	785
Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments
Segment profit	146	140	445	344
Maintenance capital	6	17	23	34
Supply and Logistics
Revenues:
External Customers	10,386	9,048	30,542	27,367
Intersegment		1	2	1
Total revenues of reportable segments	10,386	9,049	30,544	27,368
Segment Reporting, Disclosure of Other Information about Entity's Reportable Segments
Segment profit	64	142	673	544
Maintenance capital	7	4	17	11
Interest expense related to hedged inventory	$ 8	$ 3	$ 21	$ 9