Stockholders' Equity (Accumulated Other Comprehensive Income) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Currency Translation Adjustments, Balance			$ 193
Net Unrealized Gains (Losses) on Cash Flow Hedges, Balance			0
Net Unrealized Gains on Available- For-Sale Securities, Balance			2
Currency Translation Adjustments, Balance			(85)
Accumulated Other Comprehensive Income, Balance			110
Currency Translation Adjustments, Current period change	(37)	(49)	(60)	(12)
Net Unrealized Gains (Losses) on Cash Flow Hedges, Current period change	1	4	1	11
Available-for-sale Securities, Gross Realized Gain (Loss)				(1)
Net unrealized gains on available-for-sale securities, net of tax	(1)	(2)	(1)	(2)
Accumulated Other Comprehensive Income, Current period change	(37)	(47)	(60)	(3)
Currency Translation Adjustments, Balance	133		133
Net Unrealized Gains (Losses) on Cash Flow Hedges, Balance	1		1
Net Unrealized Gains on Available- For-Sale Securities, Balance	1		1
Currency Translation Adjustments, Balance	(85)		(85)
Accumulated Other Comprehensive Income, Balance	$ 50		$ 50