Property, Plant And Equipment (Summary Of Property, Plant And Equipment) (Detail) (USD $) In Millions, unless otherwise specified			12 Months Ended				12 Months Ended				12 Months Ended				12 Months Ended				12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Minimum [Member]	Dec. 31, 2013 Maximum [Member]	Dec. 31, 2013 Corporate, Non-Segment [Member]	Dec. 31, 2012 Corporate, Non-Segment [Member]	Dec. 31, 2013 Corporate, Non-Segment [Member] Minimum [Member]	Dec. 31, 2013 Corporate, Non-Segment [Member] Maximum [Member]	Dec. 31, 2013 Refining & Marketing [Member] Operating Segments [Member]	Dec. 31, 2012 Refining & Marketing [Member] Operating Segments [Member]	Dec. 31, 2013 Refining & Marketing [Member] Operating Segments [Member] Minimum [Member]	Dec. 31, 2013 Refining & Marketing [Member] Operating Segments [Member] Maximum [Member]	Dec. 31, 2013 Speedway [Member] Operating Segments [Member]	Dec. 31, 2012 Speedway [Member] Operating Segments [Member]	Dec. 31, 2013 Speedway [Member] Operating Segments [Member] Minimum [Member]	Dec. 31, 2013 Speedway [Member] Operating Segments [Member] Maximum [Member]	Dec. 31, 2013 Pipeline Transportation [Member] Operating Segments [Member]	Dec. 31, 2012 Pipeline Transportation [Member] Operating Segments [Member]	Dec. 31, 2013 Pipeline Transportation [Member] Operating Segments [Member] Minimum [Member]	Dec. 31, 2013 Pipeline Transportation [Member] Operating Segments [Member] Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives (in years)			4 years	42 years			4 years	40 years			4 years	25 years			4 years	15 years			16 years	42 years
Property, plant and equipment, gross	$ 21,793	$ 19,409			$ 546	$ 473			$ 16,982	$ 15,089			$ 2,344	$ 2,100			$ 1,921	$ 1,747
Less accumulated depreciation	7,872	6,766
Net property, plant and equipment	$ 13,921	$ 12,643