Quarterly Financial Information (unaudited) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Quarterly Financial Information (unaudited)
Net sales	$ 359.2	$ 357.8	$ 367.4	$ 361.2	$ 357.5	$ 367.5	$ 373.2	$ 329.9	$ 1,445.6	$ 1,428.1	$ 1,274.6
Gross profit	129.7	128.9	130.4	128.5	127.9	134.5	129.4	121.0	517.5	512.8	464.9
Net income from continuing operations	18.4	18.5	18.2	15.5	17.2	23.4	12.7	11.1	70.6	64.4	63.1
Net income	$ 15.5	$ 18.7	$ 18.5	$ 15.7	$ 17.0	$ 23.7	$ 14.6	$ 11.1	$ 68.4	$ 66.4	$ 58.8
Basic
Income from continuing operations (in dollars per share)	$ 0.52	$ 0.53	$ 0.50	$ 0.42	$ 0.47	$ 0.63	$ 0.34	$ 0.30	$ 1.96	$ 1.73	$ 1.69
Net income (loss) (in dollars per share)	$ 0.44	$ 0.53	$ 0.51	$ 0.42	$ 0.47	$ 0.63	$ 0.39	$ 0.30	$ 1.90	$ 1.78	$ 1.58
Diluted
Income from continuing operations (in dollars per share)	$ 0.52	$ 0.52	$ 0.50	$ 0.42	$ 0.47	$ 0.62	$ 0.34	$ 0.29	$ 1.96	$ 1.72	$ 1.69
Net income (loss) (in dollars per share)	$ 0.44	$ 0.53	$ 0.51	$ 0.42	$ 0.47	$ 0.63	$ 0.39	$ 0.29	$ 1.90	$ 1.78	$ 1.57
Dividends per common share (in dollars per share)	$ 0.11	$ 0.11	$ 0.11	$ 0.11	$ 0.11	$ 0.11	$ 0.11	$ 0.11	$ 0.44	$ 0.44	$ 0.44