Segment Information - Revenue by Geographic Area (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Revenue	$ 45,266	$ 41,731	$ 36,579
Operating Segments
Segment Reporting Information [Line Items]
Revenue	45,266	41,731	36,579
Operating Segments | North America
Segment Reporting Information [Line Items]
Revenue	13,897	13,535	12,378
Operating Segments | Latin America
Segment Reporting Information [Line Items]
Revenue	7,751	7,554	6,467
Operating Segments | Europe/CIS/Africa
Segment Reporting Information [Line Items]
Revenue	12,366	11,444	9,676
Operating Segments | Middle East & Asia
Segment Reporting Information [Line Items]
Revenue	10,810	8,775	7,722
Eliminations & other
Segment Reporting Information [Line Items]
Revenue	$ 442	$ 423	$ 336