Segment Information - Schedule of Operating Segment Reporting Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Total sales	$ 572.5	$ 540.5	$ 1,791.4	$ 1,628.1
Operating income	109.9	96.5	327.8	275.4
Depreciation and amortization	34.4	31.2	107.1	90.8
Stock-based compensation	2.4	2.0	15.9	14.0
Accrual basis additions to capital expenditures	53.3	43.5	160.9	133.5
Corporate & Other and Intersegment Elimination
Segment Reporting Information [Line Items]
Total sales	(23.3)	(17.2)	(64.1)	(56.7)
Operating income	(10.5)	(11.5)	(48.0)	(42.5)
Depreciation and amortization			0.1	0.1
Stock-based compensation	1.0	0.6	8.1	7.3
Composite Materials
Segment Reporting Information [Line Items]
Total sales	448.0	432.8	1,419.7	1,323.2
Composite Materials | Intersegment Elimination
Segment Reporting Information [Line Items]
Total sales	23.3	17.2	64.0	56.7
Composite Materials | Operating Segments
Segment Reporting Information [Line Items]
Total sales	471.3	450.0	1,483.7	1,379.9
Operating income	100.1	92.5	324.4	276.6
Depreciation and amortization	30.7	28.9	95.7	83.9
Stock-based compensation	1.2	1.2	6.4	5.7
Accrual basis additions to capital expenditures	51.0	41.4	156.8	130.1
Engineered Products
Segment Reporting Information [Line Items]
Total sales	124.5	107.7	371.7	304.9
Engineered Products | Intersegment Elimination
Segment Reporting Information [Line Items]
Total sales			0.1
Engineered Products | Operating Segments
Segment Reporting Information [Line Items]
Total sales	124.5	107.7	371.8	304.9
Operating income	20.3	15.5	51.4	41.3
Depreciation and amortization	3.7	2.3	11.3	6.8
Stock-based compensation	0.2	0.2	1.4	1.0
Accrual basis additions to capital expenditures	$ 2.3	$ 2.1	$ 4.1	$ 3.4