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, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Property, Plant and Equipment
Interest expense capitalized as construction in progress	$ 1.0	$ 0.3	$ 2.1	$ 1.4
Depreciation expense			19.6	18.3
Fabricated Products
Property, Plant and Equipment
Depreciation expense	$ 6.3	$ 6.1	$ 19.3	$ 17.9