Share-Based Compensation (Share-Based Compensation Expense) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share based compensation expense	$ 15.4	$ 13.4	$ 60.7	$ 58.1
Tax benefit	(3.7)	(3.3)	(14.7)	(14.1)
After-tax expense	11.7	10.1	46.0	44.0
Stock Options [Member]
Share based compensation expense	2.6	2.9	15.7	17.5
Restricted Stock Units (RSUs) [Member]
Share based compensation expense	3.4	4.1	20.6	22.9
Phantom Share Units (PSUs) [Member]
Share based compensation expense	5.7	5.8	20.1	12.7
Deferred Compensation [Member]
Share based compensation expense	1.1	0.8	2.9	2.3
Other share based compensation [Member]
Share based compensation expense	2.6	(0.2)	1.4	2.7
Continuing Operations [Member]
After-tax expense	11.5	8.3	44.5	38.0
Discontinued Operations [Member]
After-tax expense	$ 0.2	$ 1.8	$ 1.5	$ 6.0