Incentive Compensation Expense (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Stock-based Payment Award
Stock-based compensation expense	$ 46.0		$ 50.4		$ 62.4
Tax benefit	17.6		19.7		22.1
Stock options
Stock-based Payment Award
Stock-based compensation expense	3.7		5.4		6.7
Stock-settled awards
Stock-based Payment Award
Stock-based compensation expense	9.8		14.9		21.9
Cash-settled awards
Stock-based Payment Award
Stock-based compensation expense	1.5		3.9		5.7
Performance-based awards
Stock-based Payment Award
Stock-based compensation expense	29.6		24.5		23.3
Employee stock purchase plan
Stock-based Payment Award
Stock-based compensation expense	0.6		0.6		0.7
Other
Stock-based Payment Award
Stock-based compensation expense	0.8	[1]	1.1	[1]	4.1	[1]
Time based cash awards
Stock-based Payment Award
Incentive compensation expense, Non share-based	4.0		10.9		16.6
Performance based cash awards
Stock-based Payment Award
Incentive compensation expense, Non share-based	$ 18.3		$ 18.9		$ 22.0

[1] Represents charges recorded for severance expense related to stock-based compensation awards.