Segment Information - Revenues By Geographic Area (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Total consolidated revenues	$ 5,613	$ 5,479
United States
Segment Reporting Information [Line Items]
Total consolidated revenues	3,013	2,835
Europe, Middle East and Africa
Segment Reporting Information [Line Items]
Total consolidated revenues	1,559	1,592
Asia Pacific and Japan
Segment Reporting Information [Line Items]
Total consolidated revenues	729	722
Latin America, Mexico and Canada
Segment Reporting Information [Line Items]
Total consolidated revenues	$ 312	$ 330