Stockholders' Equity (Components Of Other Comprehensive Income) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Stockholders Equity And Comprehensive Income Loss [Line Items]
Net income	$ 280	$ 82	$ 336	$ 141
Currency translation adjustment	26	(75)	14	(37)
Net unrealized gains (losses) on available-for-sale securities, net of tax	2			2
Net unrealized gains on cash flow hedges, net of tax		8	11	24
Accumulated Other Comprehensive Income, Current period change	28	(67)	25	(11)
Total comprehensive income	$ 308	$ 15	$ 361	$ 130