Inventories (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012
Schedule of Inventories
Refinery feedstocks	$ 2,641,000,000	$ 2,458,000,000
Refined products and blendstocks	3,446,000,000	2,995,000,000
Ethanol feedstocks and products	139,000,000	191,000,000
Convenience store merchandise	0	112,000,000
Materials and supplies	220,000,000	217,000,000
Inventories	6,446,000,000	5,973,000,000
Inventories (Textual)
Excess of market value over carrying amount of LIFO inventories	$ 6,300,000,000	$ 6,700,000,000