Segment Information - Schedule of Operating Segment Reporting Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Total sales	$ 609.0	$ 547.5	$ 1,218.9	$ 1,087.6
Operating income	115.1	96.5	217.9	178.9
Depreciation and amortization	34.0	29.8	72.7	59.6
Stock-based compensation	2.4	2.1	13.5	12.0
Accrual basis additions to capital expenditures	50.1	44.7	107.6	90.0
Corporate & Other and Intersegment Elimination
Segment Reporting Information [Line Items]
Total sales	(21.5)	(20.3)	(40.8)	(39.5)
Operating income	(13.0)	(12.5)	(37.5)	(31.0)
Depreciation and amortization	0.1		0.1
Stock-based compensation	0.9	1.1	7.1	6.7
Composite Materials
Segment Reporting Information [Line Items]
Total sales	484.0	445.8	971.7	890.4
Composite Materials | Intersegment Elimination
Segment Reporting Information [Line Items]
Total sales	21.5	20.3	40.7	39.5
Composite Materials | Operating Segments
Segment Reporting Information [Line Items]
Total sales	505.5	466.1	1,012.4	929.9
Operating income	111.8	93.1	224.3	184.1
Depreciation and amortization	30.1	27.5	65.0	55.0
Stock-based compensation	1.1	0.9	5.2	4.5
Accrual basis additions to capital expenditures	49.0	43.4	105.8	88.7
Engineered Products
Segment Reporting Information [Line Items]
Total sales	125.0	101.7	247.2	197.2
Engineered Products | Intersegment Elimination
Segment Reporting Information [Line Items]
Total sales			0.1
Engineered Products | Operating Segments
Segment Reporting Information [Line Items]
Total sales	125.0	101.7	247.3	197.2
Operating income	16.3	15.9	31.1	25.8
Depreciation and amortization	3.8	2.3	7.6	4.6
Stock-based compensation	0.4	0.1	1.2	0.8
Accrual basis additions to capital expenditures	$ 1.1	$ 1.3	$ 1.8	$ 1.3