Segment Information (Details) $ in Millions	1 Months Ended	3 Months Ended									12 Months Ended
	Mar. 31, 2014 USD ($)	Dec. 31, 2015 USD ($)	[1]	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2015 USD ($) segments		Dec. 31, 2014 USD ($)		Dec. 31, 2013 USD ($)
Segment information for our reportable segments
Operating revenues		$ 18,777		$ 22,579	$ 25,118	$ 21,330	$ 27,859	$ 34,408	$ 34,914	$ 33,663	$ 87,804	[2]	$ 130,844	[2]	$ 138,074	[2]
Lower of cost or market inventory valuation adjustment											790		0		0
Depreciation and amortization expense											1,842		1,690		1,720
Operating income (loss)		$ 646		$ 2,139	$ 2,078	$ 1,495	$ 1,796	$ 1,670	$ 1,085	$ 1,351	6,358		5,902		3,957
Total expenditures for long-lived assets											$ 2,350		2,802		2,755
Segment Information (Textual)
Number of reportable segments | segments											2
Mount Vernon Ethanol Plant [Member]
Segment Information (Textual)
Payments to acquire idled corn ethanol plant	$ 34
Refining [Member]
Segment information for our reportable segments
Operating revenues											$ 84,521		126,004		129,064
Ethanol [Member]
Segment information for our reportable segments
Operating revenues											3,283		4,840		5,114
Retail [Member]
Segment information for our reportable segments
Operating revenues											0		0		3,896
Operating Segments [Member]
Segment information for our reportable segments
Operating revenues											87,955		130,944		141,078
Operating Segments [Member] | Refining [Member]
Segment information for our reportable segments
Operating revenues											84,521		126,004		131,940
Lower of cost or market inventory valuation adjustment											740
Depreciation and amortization expense											1,745		1,597		1,566
Operating income (loss)											6,973		5,884		4,211
Total expenditures for long-lived assets											2,254		2,730		2,595
Operating Segments [Member] | Ethanol [Member]
Segment information for our reportable segments
Operating revenues											3,434		4,940		5,242
Lower of cost or market inventory valuation adjustment											50
Depreciation and amortization expense											50		49		45
Operating income (loss)											142		786		491
Total expenditures for long-lived assets											67		42		33
Operating Segments [Member] | Retail [Member]
Segment information for our reportable segments
Operating revenues											0		0		3,896
Lower of cost or market inventory valuation adjustment											0
Depreciation and amortization expense											0		0		41
Operating income (loss)											0		0		81
Total expenditures for long-lived assets											0		0		62
Intersegment Eliminations [Member]
Segment information for our reportable segments
Operating revenues											(151)		(100)		(3,004)
Intersegment Eliminations [Member] | Refining [Member]
Segment information for our reportable segments
Operating revenues											0		0		(2,876)
Intersegment Eliminations [Member] | Ethanol [Member]
Segment information for our reportable segments
Operating revenues											(151)		(100)		(128)
Intersegment Eliminations [Member] | Retail [Member]
Segment information for our reportable segments
Operating revenues											0		0		0
Corporate, Non-Segment [Member] | Corporate [Member]
Segment information for our reportable segments
Depreciation and amortization expense											47		44		68
Operating income (loss)											(757)		(768)		(826)
Total expenditures for long-lived assets											$ 29		$ 30		$ 65

[1] Operating income for the quarter ended December 31, 2015 reflects a noncash lower of cost or market inventory valuation adjustment of $790 million, as described in Note 6.

[2] Includes excise taxes on sales by certain of our international operations of $5,980 million, $5,901 million, and $5,459 million.