Share-Based Compensation (Share-Based Compensation Expense) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Share based compensation expense	$ 23.0	$ 8.6
Tax benefit	(8.8)	(3.3)
After-tax expense	14.2	5.3
Stock Options [Member]
Share based compensation expense	7.9	(6.7)
Restricted Stock Units (RSUs) [Member]
Share based compensation expense	10.1	8.0
Performance Shares [Member]
Share based compensation expense	3.9	5.6
Deferred Compensation [Member]
Share based compensation expense	0.4	0.4
Other share based compensation [Member]
Share based compensation expense	$ 0.7	$ 1.3