Employee Benefits, Net Periodic Benefit Costs Segment Allocation (Details) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Allocation of Defined Benefit Plan Net Periodic Benefit Cost And Charges Relating To Other Benefit Plans, by Segment
Defined benefit plan net periodic benefit (income ) cost and (benefits) charges relating to other benefit plans	$ (0.4)	$ 2.4	$ 1.6	$ 10.0
Fabricated Products [Member]
Allocation of Defined Benefit Plan Net Periodic Benefit Cost And Charges Relating To Other Benefit Plans, by Segment
Defined benefit plan net periodic benefit (income ) cost and (benefits) charges relating to other benefit plans	1.7	1.8	7.4	7.0
All Other [Member]
Allocation of Defined Benefit Plan Net Periodic Benefit Cost And Charges Relating To Other Benefit Plans, by Segment
Defined benefit plan net periodic benefit (income ) cost and (benefits) charges relating to other benefit plans	$ (2.1)	$ 0.6	$ (5.8)	$ 3.0