Operating Segments and Geographic Data (Details 1) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Segment Assets
Goodwill	$ 4,639	$ 4,640
Total Assets	253,753	232,982
United States [Member]
Segment Assets
Total Assets	76,591	72,641
International [Member]
Segment Assets
Total Assets	172,523	155,701
Operating Segments [Member]
Segment Assets
Total Assets	231,268	205,384
Operating Segments [Member] | Upstream [Member]
Segment Assets
Goodwill	4,639	4,640
Total Assets	187,171	162,337
Operating Segments [Member] | Upstream [Member] | United States [Member]
Segment Assets
Total Assets	45,436	41,891
Operating Segments [Member] | Upstream [Member] | International [Member]
Segment Assets
Total Assets	137,096	115,806
Operating Segments [Member] | Downstream [Member]
Segment Assets
Total Assets	44,097	43,047
Operating Segments [Member] | Downstream [Member] | United States [Member]
Segment Assets
Total Assets	23,829	23,023
Operating Segments [Member] | Downstream [Member] | International [Member]
Segment Assets
Total Assets	20,268	20,024
Corporate, Non-Segment [Member]
Segment Assets
Total Assets	22,485	27,598
Corporate, Non-Segment [Member] | United States [Member]
Segment Assets
Total Assets	7,326	7,727
Corporate, Non-Segment [Member] | International [Member]
Segment Assets
Total Assets	$ 15,159	$ 19,871