Segment Information, Revenue by Product (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended											12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenue from External Customer [Line Items]
Operating revenues	$ 34,695	$ 34,726	$ 34,662	$ 35,167	[1]	$ 34,673	[2]	$ 33,713	[3]	$ 31,293	$ 26,308	$ 139,250	$ 125,987	$ 82,233
Refining [Member]
Revenue from External Customer [Line Items]
Operating revenues												122,925	109,138	69,854
Refining [Member] | Gasoline and Blendstocks [Member]
Revenue from External Customer [Line Items]
Operating revenues												55,647	49,019	33,491
Refining [Member] | Distillates [Member]
Revenue from External Customer [Line Items]
Operating revenues												51,504	43,713	26,402
Refining [Member] | Petrochemicals [Member]
Revenue from External Customer [Line Items]
Operating revenues												3,908	4,253	3,161
Refining [Member] | Lubes and Asphalts [Member]
Revenue from External Customer [Line Items]
Operating revenues												2,033	1,948	1,315
Refining [Member] | Other Product Revenues [Member]
Revenue from External Customer [Line Items]
Operating revenues												9,833	10,205	5,485
Retail [Member]
Revenue from External Customer [Line Items]
Operating revenues												12,008	11,699	9,339
Retail [Member] | Fuel Sales Gasoline and Diesel [Member]
Revenue from External Customer [Line Items]
Operating revenues												10,045	9,730	7,498
Retail [Member] | Merchandise Sales and Other [Member]
Revenue from External Customer [Line Items]
Operating revenues												1,649	1,635	1,581
Retail [Member] | Heating Oil [Member]
Revenue from External Customer [Line Items]
Operating revenues												314	334	260
Ethanol [Member]
Revenue from External Customer [Line Items]
Operating revenues												4,317	5,150	3,040
Ethanol [Member] | Ethanol Product [Member]
Revenue from External Customer [Line Items]
Operating revenues												3,545	4,436	2,647
Ethanol [Member] | Distillers Grains [Member]
Revenue from External Customer [Line Items]
Operating revenues												$ 772	$ 714	$ 393

[1] The operations of the Aruba Refinery were suspended in March 2012.

[2] Includes the operations related to the Meraux Acquisition beginning October 1, 2011.

[3] Includes the operations related to the Pembroke Acquisition beginning August 1, 2011.