Inventories (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Components of inventories
Finished goods	$ 258.0	$ 222.3
Work in process	12.0	13.2
Raw materials and repair parts	180.1	156.3
Gross inventories	450.1	391.8
Excess of current cost over last-in, first-out cost	(75.3)	(73.9)
Total inventories, net	374.8	317.9
Inventories (Textual) [Abstract]
(Loss) Income from LIFO method	$ (0.1)	$ 0.1	$ 0.7