Segment Results (Reconciliation of Total Consolidated Operating Income to Earnings Before Income Taxes) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting [Abstract]
Total consolidated operating income	$ 54.1	$ 76.0
Interest expense	5.7	6.7
Other non-operating (income) expense, net	(1.3)	369.4
Earnings (loss) from continuing operations before income taxes	$ 49.7	$ (300.1)