Accumulated Other Comprehensive Income/(Loss) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Cumulative Translation Adjustment Summary [Roll Forward]
Beginning Balance	$ (435,000,000)	$ (323,000,000)	$ (607,000,000)	$ 160,000,000
Net gain/(loss) on Foreign Currency Translation	(141,000,000)	196,000,000	31,000,000	(287,000,000)
Other Comprehensive Income (Loss), Net of Tax	(141,000,000)	196,000,000	31,000,000	(286,000,000)
Ending Balance	(576,000,000)	(127,000,000)	(576,000,000)	(127,000,000)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(576,000,000)	(127,000,000)	(576,000,000)	(127,000,000)	$ (607,000,000)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax [Abstract]
Net gain/(loss) on foreign currency translation, tax adjustment	0	0	0	0
Accumulated Other Comprehensive Income (Loss) [Member]
Cumulative Translation Adjustment Summary [Roll Forward]
Other Comprehensive Income (Loss), Net of Tax	$ (141,000,000)	$ 196,000,000	$ 31,000,000	$ (287,000,000)