Revolving Credit Facilities, Lines Of Credit And Short-Term Borrowings (Summary Of The Borrowings Outstanding And Capacity Available Under The Facility) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012
Summary of the borrowings outstanding and capacity available under the facility
Capacity	$ 3,500
Borrowings	795
Letters of Credit	8
Capacity Available	$ 2,697

Revolving Credit Facilities, Lines Of Credit And Short-Term Borrowings (Summary Of The Borrowings Outstanding And Capacity Available Under The Facility) (Details) (USD $)
In Millions, unless otherwise specified

Dec. 31, 2012

Summary of the borrowings outstanding and capacity available under the facility

$ 3,500

Borrowings

795

Letters of Credit

Capacity Available

$ 2,697