Segment and Geographical Area Information, Revenues from External Customers by Products (Details) (USD $) In Millions, 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
Revenue from External Customer
Net sales	$ 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
Aero/HS Products
Revenue from External Customer
Net sales									677.0	695.1	596.3
GE Products
Revenue from External Customer
Net sales									411.0	441.4	447.0
Automotive Extrusions
Revenue from External Customer
Net sales									129.5	125.5	126.9
Other Products
Revenue from External Customer
Net sales									$ 80.0	$ 98.1	$ 131.1