Segment Information - Revenues By Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Total consolidated revenues	$ 5,997	$ 5,880	$ 11,610	$ 11,359
United States
Segment Reporting Information [Line Items]
Total consolidated revenues	3,270	3,056	6,284	5,890
Europe, Middle East and Africa
Segment Reporting Information [Line Items]
Total consolidated revenues	1,623	1,669	3,181	3,261
Asia Pacific and Japan
Segment Reporting Information [Line Items]
Total consolidated revenues	795	802	1,524	1,525
Latin America, Mexico and Canada
Segment Reporting Information [Line Items]
Total consolidated revenues	$ 309	$ 353	$ 621	$ 683