Segment Information - Schedule of Operating Segment Reporting Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Total sales	$ 475.7	$ 470.1	$ 947.5	$ 931.8
Operating income	90.6	75.1	173.2	149.7
Other operating expense		6.0		6.0
Depreciation and amortization	18.9	17.7	37.2	34.8
Stock-based compensation expense	2.4	2.7	14.4	11.5
Accrual basis additions to capital expenditures	75.0	64.8	141.5	104.8
Operating Segments
Segment Reporting Information [Line Items]
Total sales	475.7	470.1	947.5	931.8
Composite Materials
Segment Reporting Information [Line Items]
Total sales	393.4	379.8	781.2	754.6
Operating income	91.2	79.8	180.4	155.7
Depreciation and amortization	17.3	16.3	34.0	31.9
Stock-based compensation expense	1.1	0.1	4.7	3.4
Accrual basis additions to capital expenditures	71.6	62.6	133.7	101.0
Composite Materials | Operating Segments
Segment Reporting Information [Line Items]
Total sales	373.5	361.6	740.9	717.9
Composite Materials | Intersegment Elimination
Segment Reporting Information [Line Items]
Total sales	19.9	18.2	40.3	36.7
Engineered Products
Segment Reporting Information [Line Items]
Total sales	102.2	109.0	206.7	214.5
Operating income	14.4	17.6	29.1	34.0
Depreciation and amortization	1.5	1.4	3.0	2.8
Stock-based compensation expense	0.2		0.7	0.7
Accrual basis additions to capital expenditures	3.4	2.2	7.8	3.8
Engineered Products | Operating Segments
Segment Reporting Information [Line Items]
Total sales	102.2	108.5	206.6	213.9
Engineered Products | Intersegment Elimination
Segment Reporting Information [Line Items]
Total sales		0.5	0.1	0.6
Corporate and Other
Segment Reporting Information [Line Items]
Total sales	(19.9)	(18.7)	(40.4)	(37.3)
Operating income	(15.0)	(22.3)	(36.3)	(40.0)
Other operating expense		6.0		6.0
Depreciation and amortization	0.1		0.2	0.1
Stock-based compensation expense	1.1	2.6	9.0	7.4
Corporate and Other | Intersegment Elimination
Segment Reporting Information [Line Items]
Total sales	$ (19.9)	$ (18.7)	$ (40.4)	$ (37.3)