Segment Information - Revenues By Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Information [Line Items]
Total consolidated revenues	$ 6,079	$ 6,032	$ 17,689	$ 17,391
United States
Segment Reporting Information [Line Items]
Total consolidated revenues	3,318	3,212	9,602	9,102
Europe, Middle East and Africa
Segment Reporting Information [Line Items]
Total consolidated revenues	1,630	1,672	4,811	4,933
Asia Pacific and Japan
Segment Reporting Information [Line Items]
Total consolidated revenues	787	821	2,311	2,346
Latin America, Mexico and Canada
Segment Reporting Information [Line Items]
Total consolidated revenues	$ 344	$ 327	$ 965	$ 1,010