Segment Information - Schedule of Operating Segment Reporting Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Total sales	$ 540.1	$ 478.8
Operating income	82.4	78.6
Depreciation and amortization	29.8	24.4
Stock-based compensation	9.9	10.9
Accrual basis additions to capital expenditures	45.3	92.9
Corporate & Other and Intersegment Elimination
Segment Reporting Information [Line Items]
Total sales	(19.2)	(17.1)
Operating income	(18.5)	(16.3)
Depreciation and amortization		0.1
Stock-based compensation	5.6	6.8
Composite Materials
Segment Reporting Information [Line Items]
Total sales	444.6	387.5
Composite Materials | Intersegment Elimination
Segment Reporting Information [Line Items]
Total sales	19.2	17.1
Composite Materials | Operating Segments
Segment Reporting Information [Line Items]
Total sales	463.8	404.6
Operating income	91.0	81.9
Depreciation and amortization	27.5	22.5
Stock-based compensation	3.6	3.4
Accrual basis additions to capital expenditures	45.3	86.6
Engineered Products
Segment Reporting Information [Line Items]
Total sales	95.5	91.3
Engineered Products | Operating Segments
Segment Reporting Information [Line Items]
Total sales	95.5	91.3
Operating income	9.9	13.0
Depreciation and amortization	2.3	1.8
Stock-based compensation	$ 0.7	0.7
Accrual basis additions to capital expenditures		$ 6.3