Summary of Other Income (Expense), Net (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Component of Other Income, Nonoperating [Line Items]
Interest income	$ 5		$ 6	$ 11	$ 13
Foreign exchange gain (loss)	(1)		1	(10)	(2)
Loss on extinguishment of debt					(53)
Strategic transaction expenses	(1)		(1)	(4)	(3)
Impairment of long-lived assets		(2)		(2)
Other	5		14	10	17
Other income (expense), net	$ 8		$ 20	$ 5	$ (28)