Segment Information, Net Sales by Product Categories (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Net Sales:
Net sales	$ 344.1	$ 328.9	$ 679.2	$ 666.3
Aero/HS products
Net Sales:
Net sales	173.0	165.1	336.6	344.7
GE products
Net Sales:
Net sales	107.3	110.2	219.5	216.0
Automotive Extrusions
Net Sales:
Net sales	44.7	31.0	85.5	61.8
Other products
Net Sales:
Net sales	$ 19.1	$ 22.6	$ 37.6	$ 43.8