Segment Information (Details) $ in Millions	3 Months Ended											12 Months Ended
	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)		Mar. 31, 2016 USD ($)		Dec. 31, 2015 USD ($)		Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2016 USD ($) segments		Dec. 31, 2015 USD ($)		Dec. 31, 2014 USD ($)
Segment Information for our Reportable Segments
Operating revenues	$ 20,712	$ 19,649	$ 19,584	[1]	$ 15,714	[2]	$ 18,777	[3]	$ 22,579	$ 25,118	$ 21,330	$ 75,659	[4]	$ 87,804	[4]	$ 130,844	[4]
Lower of cost or market inventory valuation adjustment			(454)		(293)		790					(747)		790		0
Depreciation and amortization expense												1,894		1,842		1,690
Asset impairment loss			56									56		0		0
Operating income (loss)	$ 620	$ 892	$ 1,231	[1]	$ 829	[2]	$ 646	[3]	$ 2,139	$ 2,078	$ 1,495	3,572		6,358		5,902
Total expenditures for long-lived assets												$ 1,996		2,350		2,802
Segment Information (Textual)
Number of reportable segments | segments												2
Refining [Member]
Segment Information for our Reportable Segments
Operating revenues												$ 71,968		84,521		126,004
Ethanol [Member]
Segment Information for our Reportable Segments
Operating revenues												3,691		3,283		4,840
Operating Segments [Member] | Refining [Member]
Segment Information for our Reportable Segments
Operating revenues												71,968		84,521		126,004
Lower of cost or market inventory valuation adjustment												(697)		740
Depreciation and amortization expense												1,780		1,745		1,597
Asset impairment loss												56
Operating income (loss)												3,995		6,973		5,884
Total expenditures for long-lived assets												1,890		2,254		2,730
Operating Segments [Member] | Ethanol [Member]
Segment Information for our Reportable Segments
Operating revenues												3,901		3,434		4,940
Lower of cost or market inventory valuation adjustment												(50)		50
Depreciation and amortization expense												66		50		49
Asset impairment loss												0
Operating income (loss)												340		142		786
Total expenditures for long-lived assets												68		67		42
Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Operating revenues												(210)		(151)		(100)
Intersegment Eliminations [Member] | Refining [Member]
Segment Information for our Reportable Segments
Operating revenues												0		0		0
Intersegment Eliminations [Member] | Ethanol [Member]
Segment Information for our Reportable Segments
Operating revenues												210		151		100
Corporate, Non-Segment [Member] | Corporate [Member]
Segment Information for our Reportable Segments
Depreciation and amortization expense												48		47		44
Asset impairment loss												0
Operating income (loss)												(763)		(757)		(768)
Total expenditures for long-lived assets												$ 38		$ 29		$ 30

[1] Operating income for the quarter ended June 30, 2016 reflects a favorable noncash lower of cost or market inventory valuation adjustment of $454 million as described in Note 4 and an asset impairment loss of $56 million related to the Aruba Disposition as described in Note 2.

[2] Operating income for the quarter ended March 31, 2016 reflects a favorable noncash lower of cost or market inventory valuation adjustment of $293 million as described in Note 4.

[3] Operating income for the quarter ended December 31, 2015 reflects an unfavorable noncash lower of cost or market inventory valuation adjustment of $790 million as described in Note 4.

[4] Includes excise taxes on sales by certain of our international operations of $5,493 million, $5,980 million, and $5,901 million.