Segment Information - Schedule of Operating Segment Reporting Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Total sales	$ 491.5	$ 500.5	$ 1,461.6	$ 1,520.8
Operating income	89.1	89.1	257.4	273.1
Depreciation and amortization	26.8	23.5	76.3	69.0
Stock-based compensation	2.2	0.8	15.5	13.6
Accrual basis additions to capital expenditures	47.9	90.4	218.0	232.6
Corporate & Other and Intersegment Elimination
Segment Reporting Information [Line Items]
Total sales	(16.4)	(16.2)	(48.6)	(53.2)
Operating income	(13.0)	(12.6)	(43.8)	(44.9)
Depreciation and amortization	0.1		0.1	0.1
Stock-based compensation	1.0		8.8	7.8
Accrual basis additions to capital expenditures		0.1		0.1
Composite Materials
Segment Reporting Information [Line Items]
Total sales	398.9	398.2	1,183.7	1,219.3
Composite Materials | Intersegment Elimination
Segment Reporting Information [Line Items]
Total sales	16.4	16.2	48.6	53.2
Composite Materials | Operating Segments
Segment Reporting Information [Line Items]
Total sales	415.3	414.4	1,232.3	1,272.5
Operating income	90.0	88.8	264.0	281.2
Depreciation and amortization	24.8	21.7	70.6	63.5
Stock-based compensation	1.1	0.7	5.7	4.9
Accrual basis additions to capital expenditures	47.4	84.4	208.5	221.6
Engineered Products
Segment Reporting Information [Line Items]
Total sales	92.6	102.3	277.9	301.5
Engineered Products | Operating Segments
Segment Reporting Information [Line Items]
Total sales	92.6	102.3	277.9	301.5
Operating income	12.1	12.9	37.2	36.8
Depreciation and amortization	1.9	1.8	5.6	5.4
Stock-based compensation	0.1	0.1	1.0	0.9
Accrual basis additions to capital expenditures	$ 0.5	$ 5.9	$ 9.5	$ 10.9