Debt (Revolving Credit Facility And Commercial Paper) (Details) (USD $) In Millions, unless otherwise specified			3 Months Ended	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 Revolving Credit Facility [Member]	Sep. 30, 2013 Revolving Credit Facility [Member]
Revolving credit facility expiration date			Dec. 01, 2017
Line of Credit Facility, Current Borrowing Capacity			$ 800.0	$ 800.0
Letter Of Credit Maximum Capacity Value			100.0	100.0
Standby letters of credit outstanding			0	0
Line of Credit Facility, Competitive Bid Loans, Max				500.0
Outstanding commercial paper obligations	$ 14.4	$ 0