Summary of Significant Accounting Policies,Textuals, Property, Plant and Equipment (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Property, Plant and Equipment
Interest expense capitalized as construction in progress	$ 0.3	$ 0.4	$ 1.4	$ 0.8
Depreciation expense			18.3	17.3
Fabricated Products
Property, Plant and Equipment
Depreciation expense	$ 6.1	$ 5.6	$ 17.9	$ 17.0