Oil Refinery (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Segment Reporting Information [Line Items]
Business Acquisition, Date of Acquisition Agreement					Jun. 22, 2012
Operating Revenue	$ 10,621		$ 9,707		$ 19,537		$ 18,207
Exchanged products [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenue	$ (1,524)	[1]	$ (1,347)	[1]	$ (2,527)	[1]	$ (2,668)	[1]

[1] Represents value of products delivered under our strategic agreements, as discussed above, determined on a market price basis.