Financial and Derivative Instruments (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Consolidated Statement of Income: The Effect of Derivatives not Designated as Hedging Instruments
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 67	$ (120)	$ 54	$ (122)
Commodity [Member] | Sales and other operating revenues [Member]
Consolidated Statement of Income: The Effect of Derivatives not Designated as Hedging Instruments
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	86	(85)	112	(48)
Commodity [Member] | Purchased crude oil and products [Member]
Consolidated Statement of Income: The Effect of Derivatives not Designated as Hedging Instruments
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(16)	(37)	(32)	(69)
Commodity [Member] | Other income [Member]
Consolidated Statement of Income: The Effect of Derivatives not Designated as Hedging Instruments
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (3)	$ 2	$ (26)	$ (5)