Segment Information - Revenues By Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Segment Reporting Information [Line Items]
Total consolidated revenues	$ 5,475	$ 5,613
United States
Segment Reporting Information [Line Items]
Total consolidated revenues	2,897	3,013
Europe, Middle East and Africa
Segment Reporting Information [Line Items]
Total consolidated revenues	1,537	1,559
Asia Pacific and Japan
Segment Reporting Information [Line Items]
Total consolidated revenues	740	729
Latin America, Mexico and Canada
Segment Reporting Information [Line Items]
Total consolidated revenues	$ 301	$ 312