Share-Based Compensation (Share-Based Compensation Expense) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Share based compensation expense	$ 24.5	$ 26.3
Tax benefit	(9.4)	(10.1)
After-tax expense	15.1	16.2
Stock Options [Member]
Share based compensation expense	6.7	6.5
Restricted Stock Units (RSUs) [Member]
Share based compensation expense	9.0	10.2
Performance Shares [Member]
Share based compensation expense	7.6	9.6
Other share based compensation [Member]
Share based compensation expense	$ 1.2	$ 0