Selected Quarterly Financial Information (unaudited) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Summary of information on net sales, gross profit, net income, earnings per share and dividends per share
Net Sales	$ 812.8	$ 898.4	$ 960.7	$ 695.4	$ 749.5	$ 868.0	$ 913.1	$ 668.4	$ 3,367.4	[1]	$ 3,199.1	[1]	$ 2,949.4	[1]
Gross Profit	225.4	247.1	262.6	168.1	207.7	237.4	254.0	162.0	903.3		861.2		722.3
Net income	$ 44.6	$ 67.4	$ 73.9	$ 19.9	$ 35.2	$ 64.3	$ 64.3	$ 8.0	$ 205.8		$ 171.8		$ 90.0
Basic Earnings (Loss) per Share	$ 0.98	$ 1.40	$ 1.51	$ 0.41	$ 0.72	$ 1.29	$ 1.28	$ 0.16	$ 4.30		$ 3.45		$ 1.77
Diluted Earnings (Loss) per Share	$ 0.96	$ 1.38	$ 1.49	$ 0.40	$ 0.70	$ 1.27	$ 1.26	$ 0.16	$ 4.23		$ 3.39		$ 1.75
Dividends per Common Share	$ 0.3	$ 0.3	$ 0.3	$ 0.24	$ 0.24	$ 0.24	$ 0.24	$ 0.2	$ 1.14		$ 0.92		$ 0.76

[1] On a consolidated basis, no revenue from transactions with a single customer were 10% or greater of our consolidated net sales for any of the periods presented.