Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011 Segment	Dec. 31, 2010	Dec. 31, 2009
Segment Information
Number of reporting segments									2
Segment information
Third-Party Sales	$ 355.3	$ 351.8	$ 353.7	$ 331.6	$ 311.0	$ 294.5	$ 305.1	$ 263.0	$ 1,392.4	$ 1,173.6	$ 1,108.3
Operating income (loss)	49.4	46.0	49.4	47.2	31.0	34.5	40.5	23.8	192.0	129.8	103.7
Depreciation									55.3	53.2	46.6
Equity in earnings from affiliated companies									1.6	0.5	0.7
Other (income) expense, net		2.7		(5.7)				3.5	(3.0)	3.5	7.5
Segment assets	1,376.1				1,258.1				1,376.1	1,258.1	1,246.6
Investments in affiliated companies	21.7				19.9				21.7	19.9	17.7
Accrual basis additions to property, plant and equipment									184.5	60.7	85.7
Composite Materials
Segment information
Third-Party Sales									1,074.5	904.5	856.5
Intersegment sales									53.8	38.7	27.2
Operating income (loss)									194.5	139.6	111.4
Depreciation									50.8	49.1	42.3
Other (income) expense, net									(5.7)		8.4
Segment assets	1,076.0				919.9				1,076.0	919.9	957.3
Accrual basis additions to property, plant and equipment									176.6	57.3	82.7
Engineered Products
Segment information
Third-Party Sales									317.9	269.1	251.8
Intersegment sales									1.6	0.6	0.1
Operating income (loss)									51.6	45.7	36.0
Depreciation									4.3	3.9	4.1
Equity in earnings from affiliated companies									1.6	0.5	0.7
Segment assets	192.3				176.8				192.3	176.8	172.9
Investments in affiliated companies	21.7				19.9				21.7	19.9	17.7
Accrual basis additions to property, plant and equipment									6.9	3.3	2.4
Corporate and Other
Segment information
Intersegment sales									(55.4)	(39.3)	(27.3)
Operating income (loss)									(54.1)	(55.5)	(43.7)
Depreciation									0.2	0.2	0.2
Other (income) expense, net									2.7	3.5	(0.9)
Segment assets	107.8				161.4				107.8	161.4	116.4
Accrual basis additions to property, plant and equipment									$ 1.0	$ 0.1	$ 0.6