Risk Management (Summary Of Fair Values And Location In Condensed Consolidated Balance Sheet) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	$ 3	$ 1
Fair value of derivative liabilities	7	8
Designated As Hedging Instruments | Foreign Exchange Contracts | Other Assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	1	0
Designated As Hedging Instruments | Foreign Exchange Contracts | Other Liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	0	2
Not Designated As Hedging Instruments
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	2	1
Fair value of derivative liabilities	7	6
Not Designated As Hedging Instruments | Foreign Exchange Contracts | Other Assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	2	1
Not Designated As Hedging Instruments | Foreign Exchange Contracts | Other Liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	3	3
Not Designated As Hedging Instruments | Interest Agreement Contracts | Other Assets
Derivatives, Fair Value [Line Items]
Fair value of derivative assets	0	0
Not Designated As Hedging Instruments | Interest Agreement Contracts | Other Liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative liabilities	$ 4	$ 3