Accumulated Other Comprehensive Income/(Loss) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	$ (364)	$ 117
Other comprehensive income/(loss) before reclassifications	(400)	3
Amounts reclassified from accumulated other comprehensive income/(loss)	1	1
Other comprehensive income/(loss)	(399)	4
Balance at end of period	(763)	121
Foreign currency translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(359)	122
Other comprehensive income/(loss) before reclassifications	(401)	5
Amounts reclassified from accumulated other comprehensive income/(loss)	0	0
Other comprehensive income/(loss)	(401)	5
Balance at end of period	(760)	127
Derivative financial instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(5)	(5)
Other comprehensive income/(loss) before reclassifications	1	(2)
Amounts reclassified from accumulated other comprehensive income/(loss)	1	1
Other comprehensive income/(loss)	2	(1)
Balance at end of period	$ (3)	$ (6)