Share-Based Compensation Plans (Schedule of Cash Proceeds, Tax Benefits and Intrinsic Value Related to Stock Options) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Proceeds from Stock Options Exercised	$ 16.8	[1]	$ 23.9	[1]	$ 13.1	[1]
Tax benefit realized for stock options exercised	1.3		3.3		0.9
Intrinsic value of stock options exercised	$ 10.0		$ 14.6		$ 5.0

[1] Non-cash financing activities included the change in fair market value of interest-rate swap agreements of $53.2 in 2011, $66.8 in 2010, and $(55.7) in 2009 (see Note 5, Debt and Other Financing).