Debt (Revolving Credit Facility And Commercial Paper) (Details) (USD $)			12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 $800 Million Credit Facility [Member]
Amount available for borrowing			$ 800,000,000
Amount available for borrowing			1,250,000,000
Maximum amount of letters of credit issuable under the facility			100,000,000
Revolving credit facility expiration date			Dec. 31, 2018
Outstanding commercial paper obligations	95,000,000	0
Line of Credit Facility, Competitive Bid Loans, Max			$ 500,000,000