Quarterly Financial and Market Data (Unaudited) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Quarterly Financial and Market Data (Unaudited)
Net sales	$ 355.3	$ 351.8	$ 353.7	$ 331.6	$ 311.0	$ 294.5	$ 305.1	$ 263.0	$ 1,392.4	$ 1,173.6	$ 1,108.3
Gross margin	85.6	86.5	87.0	83.0	67.6	70.5	78.4	66.1	342.1	282.6	248.5
Other (income) expense, net		2.7		(5.7)				3.5	(3.0)	3.5	7.5
Operating income	49.4	46.0	49.4	47.2	31.0	34.5	40.5	23.8	192.0	129.8	103.7
Net income	$ 39.5	$ 32.2	$ 37.4	$ 26.4	$ 22.9	$ 15.6	$ 23.1	$ 15.8
Net income per common share:
Basic	$ 0.40	$ 0.33	$ 0.38	$ 0.27	$ 0.23	$ 0.16	$ 0.24	$ 0.16	$ 1.37	$ 0.79	$ 0.58
Diluted	$ 0.39	$ 0.32	$ 0.37	$ 0.26	$ 0.23	$ 0.16	$ 0.23	$ 0.16	$ 1.35	$ 0.77	$ 0.57
Market price:
High (in dollars per share)	$ 25.84	$ 24.23	$ 21.90	$ 20.69	$ 19.08	$ 19.21	$ 17.28	$ 14.44
Low (in dollars per share)	$ 21.34	$ 18.07	$ 18.78	$ 17.58	$ 15.67	$ 15.06	$ 14.01	$ 10.13