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, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting [Abstract]
Total consolidated operating income	$ 69.0	$ 71.0	$ 210.4	$ 144.3
Interest expense	9.1	9.0	27.5	43.4
Other non-operating expense	1.7		3.6
Other non-operating (income)	(3.0)	(1.6)	(7.4)	(8.9)
Earnings from continuing operations before income taxes	$ 61.2	$ 63.6	$ 186.7	$ 109.8