Operating Segments and Geographic Data (Details 1) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Segment Assets
Segment Assets	$ 268,449	$ 266,026
Goodwill	4,588	4,593
United States [Member]
Segment Assets
Segment Assets	75,521	79,014
International [Member]
Segment Assets
Segment Assets	188,340	182,419
Operating Segments [Member]
Segment Assets
Segment Assets	250,867	247,325
Operating Segments [Member] | Upstream [Member]
Segment Assets
Segment Assets	213,059	206,534
Goodwill	4,588	4,593
Operating Segments [Member] | Upstream [Member] | United States [Member]
Segment Assets
Segment Assets	48,638	49,205
Operating Segments [Member] | Upstream [Member] | International [Member]
Segment Assets
Segment Assets	159,833	152,736
Operating Segments [Member] | Downstream [Member]
Segment Assets
Segment Assets	37,808	40,791
Operating Segments [Member] | Downstream [Member] | United States [Member]
Segment Assets
Segment Assets	21,579	23,068
Operating Segments [Member] | Downstream [Member] | International [Member]
Segment Assets
Segment Assets	16,229	17,723
Corporate, Non-Segment [Member]
Segment Assets
Segment Assets	17,582	18,701
Corporate, Non-Segment [Member] | United States [Member]
Segment Assets
Segment Assets	5,304	6,741
Corporate, Non-Segment [Member] | International [Member]
Segment Assets
Segment Assets	$ 12,278	$ 11,960