Business Group Information - Schedule of Revenues By Geographic Area Based On The Location of Customers (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Revenues	$ 31,218	$ 31,513	$ 32,677
North America
Segment Reporting Information [Line Items]
Revenues	25,808	26,047	27,246
North America | United States
Segment Reporting Information [Line Items]
Revenues	24,845	25,004	26,401
North America | Canada
Segment Reporting Information [Line Items]
Revenues	923	878	806
North America | Other North America
Segment Reporting Information [Line Items]
Revenues	40	165	39
Europe
Segment Reporting Information [Line Items]
Revenues	2,841	3,076	2,957
Europe | United Kingdom
Segment Reporting Information [Line Items]
Revenues	881	1,027	857
Europe | Switzerland
Segment Reporting Information [Line Items]
Revenues	541	679	582
Europe | Russia
Segment Reporting Information [Line Items]
Revenues	244	548	287
Europe | Spain
Segment Reporting Information [Line Items]
Revenues	201	288	405
Europe | Other Europe
Segment Reporting Information [Line Items]
Revenues	974	534	826
Asia Pacific
Segment Reporting Information [Line Items]
Revenues	1,486	1,417	1,484
Asia Pacific | China
Segment Reporting Information [Line Items]
Revenues	987	876	929
Asia Pacific | Other Asia Pacific
Segment Reporting Information [Line Items]
Revenues	499	541	555
Africa Middle East
Segment Reporting Information [Line Items]
Revenues	748	713	672
South America
Segment Reporting Information [Line Items]
Revenues	$ 335	$ 260	$ 318