Accumulated Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Cumulative Translation Adjustment Summary [Roll Forward]
Beginning balance			$ 743	$ 600
Net gain/(loss) on foreign currency translation			(62)	141
Ending balance	741	741	741	741
Total AOCI ending balance at September 30	741	741	741	741	743
Total other comprehensive income/(loss), net of tax	176	185	(62)	141
Accumulated Translation Adjustment [Member]
Cumulative Translation Adjustment Summary [Roll Forward]
Net gain/(loss) on foreign currency translation			60	0
Accumulated Other Comprehensive Income (Loss) [Member]
Cumulative Translation Adjustment Summary [Roll Forward]
Total other comprehensive income/(loss), net of tax			$ (2)	$ 141