Segment Results (Reconciliation of Total Consolidated Operating Income to Earnings Before Income Taxes) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting [Abstract]
Total consolidated operating income	$ 72.1	$ 72.3	$ 204.5	$ 210.7
Interest expense	6.1	6.1	17.4	18.7
Other non-operating (income) expense, net	(1.4)	(3.2)	(4.3)	361.8
Earnings (loss) from continuing operations before income taxes	$ 67.4	$ 69.4	$ 191.4	$ (169.8)