Property, Plant and Equipment (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Property Plant and Equipment, at cost
Property, plant and equipment, at cost	$ 9,584	$ 9,123
Accumulated depreciation	(2,496)	(2,248)
Net property, plant and equipment	7,088	6,875
Refining
Property Plant and Equipment, at cost
Property, plant and equipment, at cost	6,820	6,546
TLLP
Property Plant and Equipment, at cost
Property, plant and equipment, at cost	1,710	1,569
Retail
Property Plant and Equipment, at cost
Property, plant and equipment, at cost	812	778
Corporate
Property Plant and Equipment, at cost
Property, plant and equipment, at cost	$ 242	$ 230