Inventories (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule of Inventories
Refinery feedstocks	$ 2,135,000,000	$ 2,458,000,000
Refined products and blendstocks	3,231,000,000	2,995,000,000
Ethanol feedstocks and products	166,000,000	191,000,000
Convenience store merchandise	0	112,000,000
Materials and supplies	226,000,000	217,000,000
Inventories	5,758,000,000	5,973,000,000
Inventories (Textual)
Effect of LIFO inventory liquidation on income, increase (decrease)	17,000,000	134,000,000	247,000,000
Excess of market value over carrying amount of LIFO inventories	6,900,000,000	6,700,000,000
Inventory not valued at LIFO	$ 851,000,000	$ 878,000,000