Condensed Consolidated Statements of Comprehensive (Loss)/Income (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement Of Income And Comprehensive Income [Abstract]
Foreign currency translation adjustments, tax	$ (4)	$ (2)	$ (5)	$ 7
Available-for-sale securities, tax	0	(2)	(3)	(6)
Changes in the fair value of cash flow hedges, tax	(2)	1	(2)	(4)
Defined benefit pension plan adjustments, tax	$ (1)	$ 0	$ 0	$ (16)