Derivatives and Hedging (Details 2) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Derivatives designated as hedging instruments | Interest rate swaps | Fair value hedges | Other current assets
Derivatives designated as hedging and not designated as hedging instruments
Derivatives at fair value	$ 6	$ 5
Derivatives designated as hedging instruments | Interest rate swaps | Fair value hedges | Other assets
Derivatives designated as hedging and not designated as hedging instruments
Derivatives at fair value		31
Derivatives designated as hedging instruments | Interest rate swaps | Cash flow hedges | Other long-term liabilities
Derivatives designated as hedging and not designated as hedging instruments
Derivatives at fair value	15	16
Derivatives designated as hedging instruments | Cross-currency swaps | Cash flow hedges | Other current assets
Derivatives designated as hedging and not designated as hedging instruments
Derivatives at fair value	1
Derivatives designated as hedging instruments | Cross-currency swaps | Cash flow hedges | Other long-term liabilities
Derivatives designated as hedging and not designated as hedging instruments
Derivatives at fair value	3	7
Nondesignated | Interest rate swaps | Other long-term liabilities
Derivatives designated as hedging and not designated as hedging instruments
Derivatives at fair value		$ 15