Goodwill and Other Intangible Assets, Net - Other Intangible Assets (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 217.3	$ 220.9
Accumulated amortization	(83.7)	(64.6)
Finite-live intangible asset, net	133.6	156.3
Indefinite-lived intangible assets, gross/net carrying amount	26.7	30.9
Other intangible assets	244.0	251.8
Other intangible assets, net	160.3	187.2
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	155.8	157.4
Accumulated amortization	(59.3)	(45.3)
Finite-live intangible asset, net	$ 96.5	112.1
Finite-Lived Intangible Asset, Useful Life	12 years 8 months 12 days
Proprietary technology [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 52.5	54.9
Accumulated amortization	(16.8)	(12.7)
Finite-live intangible asset, net	$ 35.7	42.2
Finite-Lived Intangible Asset, Useful Life	13 years 7 months 6 days
Patents and Other [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 9.0	8.6
Accumulated amortization	(7.6)	(6.6)
Finite-live intangible asset, net	$ 1.4	$ 2.0
Finite-Lived Intangible Asset, Useful Life	9 years 3 months 18 days
Wolverine Advanced Materials Acquisition [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets, gross/net carrying amount	$ 7.0
Other intangible assets	86.0
Wolverine Advanced Materials Acquisition [Member] | Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 61.0
Finite-Lived Intangible Asset, Useful Life	9 years
Wolverine Advanced Materials Acquisition [Member] | Proprietary technology [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 18.0
Finite-Lived Intangible Asset, Useful Life	10 years
Hartzell Aerospace Acquisition [Member]
Finite-Lived Intangible Assets [Line Items]
Other intangible assets	$ 28.6
Hartzell Aerospace Acquisition [Member] | Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 16.9
Finite-Lived Intangible Asset, Useful Life	20 years
Hartzell Aerospace Acquisition [Member] | Proprietary technology [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 9.6
Finite-Lived Intangible Asset, Useful Life	20 years
Hartzell Aerospace Acquisition [Member] | Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 1.9
Finite-Lived Intangible Asset, Useful Life	1 year
Hartzell Aerospace Acquisition [Member] | Brands and Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 0.2
Finite-Lived Intangible Asset, Useful Life	1 year