Equity Investment (Summary of Investment in Joint Venture, Income Statement Data) (Details) - WAVE [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Schedule of Equity Method Investments [Line Items]
Net sales	$ 101.6	$ 102.6	$ 311.1	$ 300.5
Gross profit	49.7	54.0	157.5	160.9
Net earnings	$ 31.3	$ 41.8	$ 114.1	$ 124.0