Goodwill and Purchased Intangible Assets - Schedule of Gross Goodwill and Other Purchased Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Changes in the carrying amount of gross goodwill and other purchased intangibles
Balance at the beginning of the period	$ 142.3	$ 148.7
Amortization expense	(6.9)	(2.9)
Additions	145.1
Currency translation adjustments and other	(0.1)	(3.5)
Balance at the end of the period	280.4	142.3
Composite Materials
Changes in the carrying amount of gross goodwill and other purchased intangibles
Balance at the beginning of the period	98.2	103.7
Amortization expense	(2.0)	(2.0)
Currency translation adjustments and other		(3.5)
Balance at the end of the period	96.2	98.2
Engineered Products
Changes in the carrying amount of gross goodwill and other purchased intangibles
Balance at the beginning of the period	44.1	45.0
Amortization expense	(4.9)	(0.9)
Additions	145.1
Currency translation adjustments and other	(0.1)
Balance at the end of the period	$ 184.2	$ 44.1