Hedging Hedging Narrative (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		36 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Foreign currency cash flow hedge (gain) loss to be reclassified during next 12 months	$ 2		$ 2
(Gain) loss on foreign currency derivative instruments not designated as hedging instruments	(4)	3	(1)	10
Transaction losses (gains) on net monetary assets	$ 12	$ (4)	$ 8	$ (12)
Maximum length of time hedged in price risk cash flow hedge					3 years