Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended										12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013		Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012		Dec. 31, 2013 segments	Dec. 31, 2012	Dec. 31, 2011
Segment information for our three reportable segments
Operating revenues	$ 34,429	$ 36,137	$ 34,034	[1]	$ 33,474	$ 34,695	$ 34,726	$ 34,662	$ 35,167	[1],[2]	$ 138,074	$ 139,250	$ 125,987
Depreciation and amortization expense											1,720	1,574	1,534
Operating income (loss)	1,562	532	808	[1]	1,061	1,584	1,309	1,361	(244)	[1],[2]	3,963	4,010	3,680
Total expenditures for long-lived assets											2,757	3,413	2,987
Segment Information (Textual)
Number of reportable segments											2
Refining [Member]
Segment information for our three reportable segments
Operating revenues											129,064	122,925	109,138
Retail [Member]
Segment information for our three reportable segments
Operating revenues											3,896	12,008	11,699
Ethanol [Member]
Segment information for our three reportable segments
Operating revenues											5,114	4,317	5,150
Corporate, Non-Segment [Member] | Corporate and Other [Member]
Segment information for our three reportable segments
Operating revenues											0	0	0
Depreciation and amortization expense											68	43	42
Operating income (loss)											(826)	(741)	(613)
Total expenditures for long-lived assets											65	66	113
Operating Segments [Member] | Refining [Member]
Segment information for our three reportable segments
Operating revenues											129,064	122,925	109,138
Depreciation and amortization expense											1,566	1,370	1,338
Operating income (loss)											4,217	4,450	3,516
Total expenditures for long-lived assets											2,597	3,147	2,708
Operating Segments [Member] | Retail [Member]
Segment information for our three reportable segments
Operating revenues											3,896	12,008	11,699
Depreciation and amortization expense											41	119	115
Operating income (loss)											81	348	381
Total expenditures for long-lived assets											62	164	134
Operating Segments [Member] | Ethanol [Member]
Segment information for our three reportable segments
Operating revenues											5,114	4,317	5,150
Depreciation and amortization expense											45	42	39
Operating income (loss)											491	(47)	396
Total expenditures for long-lived assets											33	36	32
Intersegment Eliminations [Member]
Segment information for our three reportable segments
Operating revenues											3,004	9,061	8,810
Intersegment Eliminations [Member] | Refining [Member]
Segment information for our three reportable segments
Operating revenues											2,876	8,946	8,665
Intersegment Eliminations [Member] | Retail [Member]
Segment information for our three reportable segments
Operating revenues											0	0	0
Intersegment Eliminations [Member] | Ethanol [Member]
Segment information for our three reportable segments
Operating revenues											$ 128	$ 115	$ 145

[1] The separation of our retail business was completed on May 1, 2013.

[2] The operations of the Aruba Refinery were suspended in March 2012.