Selected Quarterly Financial Information (unaudited) (Quarterly Information) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Net Sales	$ 897.3	$ 1,010.0	$ 1,019.2	$ 715.2	$ 834.1	$ 955.0	$ 992.5	$ 685.8	$ 3,641.6	$ 3,467.4	$ 3,367.4
Gross Profit	267.6	310.3	315.0	183.6	227.6	273.4	283.4	163.0	1,076.5	947.4	903.3
Net Income (Loss)	$ 40.4	$ 101.7	$ 110.7	$ 24.9	$ 11.2	$ 80.3	$ 81.2	$ 13.9	$ 277.8	$ 186.6	$ 205.8
Basic Earnings (Loss) per Share (in usd per share)	$ 0.94	$ 2.35	$ 2.54	$ 0.57	$ 0.25	$ 1.78	$ 1.80	$ 0.31	$ 6.39	$ 4.16	$ 4.30
Diluted Earnings (Loss) per Share (in usd per share)	0.93	2.33	2.51	0.56	0.25	1.76	1.78	0.31	6.32	4.09	4.23
Cash Dividends per Common Share (in usd per share)	$ 0.43	$ 0.43	$ 0.43	$ 0.36	$ 0.36	$ 0.36	$ 0.36	$ 0.30	$ 1.65	$ 1.38	$ 1.14