Derivatives Derivatives (Details 5-Non Hedges) (Details) (Not Designated as Hedging Instrument [Member], Commodity [Member], Sales and other operating revenues [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Not Designated as Hedging Instrument [Member] | Commodity [Member] | Sales and other operating revenues [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Income, Net	$ (86)	$ 45	$ (73)	$ 46