Segment Information - Revenues By Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Total consolidated revenues	$ 6,017	$ 5,997	$ 11,492	$ 11,610
United States
Segment Reporting Information [Line Items]
Total consolidated revenues	3,289	3,270	6,186	6,284
Europe, Middle East and Africa
Segment Reporting Information [Line Items]
Total consolidated revenues	1,673	1,623	3,210	3,181
Asia Pacific and Japan
Segment Reporting Information [Line Items]
Total consolidated revenues	762	795	1,502	1,524
Latin America, Mexico and Canada
Segment Reporting Information [Line Items]
Total consolidated revenues	$ 293	$ 309	$ 594	$ 621