Segment Information (Schedule Of Revenues By Product Line) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Sales and other operating revenues (including consumer excise taxes)	$ 72,051	$ 97,817	$ 100,160
Refined products
Segment Reporting Information [Line Items]
Sales and other operating revenues (including consumer excise taxes)	63,708	90,702	93,520
Merchandise
Segment Reporting Information [Line Items]
Sales and other operating revenues (including consumer excise taxes)	5,188	3,817	3,308
Crude oil and refinery feedstocks
Segment Reporting Information [Line Items]
Sales and other operating revenues (including consumer excise taxes)	2,718	2,917	2,988
Transportation and other
Segment Reporting Information [Line Items]
Sales and other operating revenues (including consumer excise taxes)	$ 437	$ 381	$ 344