Operating Segments and Geographic Data (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Information [Line Items]
Segment Earnings	$ 2,037	$ 5,593	$ 5,175	$ 15,770
Operating Segments [Member]
Segment Reporting Information [Line Items]
Segment Earnings	2,270	6,036	5,990	17,038
Operating Segments [Member] | Upstream [Member]
Segment Reporting Information [Line Items]
Segment Earnings	59	4,649	(600)	14,220
Operating Segments [Member] | Upstream [Member] | United States [Member]
Segment Reporting Information [Line Items]
Segment Earnings	(603)	929	(2,101)	2,895
Operating Segments [Member] | Upstream [Member] | International [Member]
Segment Reporting Information [Line Items]
Segment Earnings	662	3,720	1,501	11,325
Operating Segments [Member] | Downstream [Member]
Segment Reporting Information [Line Items]
Segment Earnings	2,211	1,387	6,590	2,818
Operating Segments [Member] | Downstream [Member] | United States [Member]
Segment Reporting Information [Line Items]
Segment Earnings	1,249	809	2,686	1,748
Operating Segments [Member] | Downstream [Member] | International [Member]
Segment Reporting Information [Line Items]
Segment Earnings	962	578	3,904	1,070
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Interest Income	16	16	49	54
Other	$ (249)	$ (459)	$ (864)	$ (1,322)