Nature of Operations (Reconciliation Of Total Consolidated Operating Income To Earnings Before Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Total consolidated operating income	$ 254.8	$ 317.4	$ 249.4
Interest expense	24.1	38.4	39.2
Other non-operating expense (income), net	357.4	(20.4)	(32.5)
(Loss) earnings from continuing operations before income taxes	$ (126.7)	$ 299.4	$ 242.7