Segment Results (Reconciliation of Total Consolidated Operating Income to Earnings Before Income Taxes) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting [Abstract]
Total consolidated operating income	$ 78.4	$ 51.7	$ 141.4	$ 73.3
Interest expense	9.2	12.5	18.4	34.4
Other non-operating expense	0.1		1.9
Other non-operating (income)	(1.0)	(2.1)	(4.4)	(7.3)
Earnings from continuing operations before income taxes	$ 70.1	$ 41.3	$ 125.5	$ 46.2