Segment Information (Details) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Net sales to external customers:
Total Net sales to external customers	$ 1,329.6	$ 1,011.4	$ 2,583.7	$ 1,925.1
Intersegment sales:
Total Intersegment sales	32.5	21.4	67.0	44.2
Segment EBIT:
Total EBIT for reportable segments	212.5	146.0	409.4	241.5
Unallocated corporate expenses	(20.4)	(17.8)	(38.4)	(32.2)
Interest expense	(9.3)	(10.0)	(19.1)	(19.6)
Interest income	1.4	0.9	2.9	1.5
Intersegment adjustments	(0.4)	1.1	0.2	3.6
Income From Continuing Operations Before Income Taxes	183.8	120.2	355.0	194.8
Mobile Industries [Member]
Net sales to external customers:
Total Net sales to external customers	465.1	400.4	908.0	767.9
Intersegment sales:
Total Intersegment sales	0.1		0.2
Segment EBIT:
Total EBIT for reportable segments	66.8	68.6	134.8	108.2
Process Industries [Member]
Net sales to external customers:
Total Net sales to external customers	307.5	211.0	591.6	416.9
Intersegment sales:
Total Intersegment sales	0.8	0.6	1.7	1.3
Segment EBIT:
Total EBIT for reportable segments	70.3	28.3	137.0	52.4
Aerospace and Defense [Member]
Net sales to external customers:
Total Net sales to external customers	83.5	82.7	162.6	174.8
Segment EBIT:
Total EBIT for reportable segments	3.3	6.1	5.5	18.0
Steel [Member]
Net sales to external customers:
Total Net sales to external customers	473.5	317.3	921.5	565.5
Intersegment sales:
Total Intersegment sales	31.6	20.8	65.1	42.9
Segment EBIT:
Total EBIT for reportable segments	$ 72.1	$ 43.0	$ 132.1	$ 62.9