Share-Based Payments Compensation Expense (Details) - Options and Sosars [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense (in dollars)	$ 4.9	$ 3.8	$ 8.1	$ 12.1
Tax benefit (in dollars)	(1.3)	(1.2)	(2.1)	(3.9)
After-tax compensation expense (in dollars)	$ 3.6	$ 2.6	$ 6.0	$ 8.2