Equity Investment (Summary of Investment in Joint Venture, Income Statement Data) (Details) - WAVE [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Schedule of Equity Method Investments [Line Items]
Net sales	$ 107.7	$ 104.0	$ 209.5	$ 197.9
Gross profit	55.6	56.6	107.8	106.9
Net earnings	$ 43.2	$ 43.0	$ 82.8	$ 82.2