Stock Based Compensation Plans (Summary Of Option Activity) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 Y
Stock Based Compensation Plans [Abstract]
Outstanding at December 31, 2011, Options	8.3
Granted, Options	0
Exercised, Options	(0.4)
Cancelled, Options	0
Outstanding at March 31, 2012, Options	7.9
Exercisable at March 31, 2012, Options	4.2
Outstanding at December 31, 2011, Weighted-Average Exercise Price	$ 26.39
Granted, Weighted-Average Exercise Price	$ 0.00
Exercised, Weighted-Average Exercise Price	$ 15.80
Cancelled, Weighted-Average Exercise Price	$ 0.00
Outstanding at March 31, 2012, Weighted-Average Exercise Price	$ 26.83
Exercisable at March 31, 2012, Weighted-Average Exercise Price	$ 21.07
Outstanding at March 31, 2012, Weighted-Average Remaining Contractual Term, years	5.9
Exercisable at March 31, 2012, Weighted-Average Remaining Contractual Term, years	4.2
Outstanding at March 31, 2012, Aggregate Intrinsic Value	$ 176.5
Exercisable at March 31, 2012, Aggregate Intrinsic Value	$ 118.5