Acquisitions, Alexco Pro Forma Table (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Net sales (combined)	$ 311.3	$ 319.9	$ 328.9	$ 337.4	$ 314.0	$ 335.5	$ 345.2	$ 365.4	$ 1,297.5		$ 1,360.1		$ 1,301.3
Net income (combined)	27.3	25.4	18.6	33.5	9.1	29.2	21.0	26.5	104.8		85.8		25.1
Basic earnings per share (combined)	$ 1.48	$ 1.37	$ 0.99	$ 1.75	$ 0.48	$ 1.52	$ 1.10	$ 1.39	$ 5.56		$ 4.49		$ 1.32
Diluted earnings per share (combined)	$ 1.44	$ 1.34	$ 0.98	$ 1.73	$ 0.47	$ 1.51	$ 1.09	$ 1.38	$ 5.44	[1],[2]	$ 4.45	[1],[2]	$ 1.32	[1],[2]
Business Acquisition, Pro Forma Information
Net sales (combined)															1,110.7
Net income (combined)															16.9
Basic earnings per share (combined)															$ 0.87
Diluted earnings per share (combined)															$ 0.87
Alexco
Business Acquisition, Pro Forma Information
Net sales									39.5		44.5		42.8
Net income before income taxes									$ 6.3		$ 9.0		$ 10.5

[1] The diluted weighted-average number of common shares outstanding and diluted earnings per share for 2013 and 2012 were calculated using the treasury method. The diluted weighted-average number of common shares outstanding and diluted earnings per share for 2011 were calculated using the two-class method (see Note 1).

[2] Diluted weighted-average number of common shares outstanding and diluted earnings per share for 2013 and 2012 are based on the treasury method. Diluted weighted-average number of common shares outstanding and diluted earnings per share for 2011 is based on the two-class method (see Note 1 and Note 13).