Goodwill and Other Identifiable Intangible Assets - Detail of Identifiable Intangible Assets (Detail) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Acquired Intangible Assets By Major Class [Line Items]
Finite-Lived Intangible Assets, Gross	$ 468.1	$ 479.4
Accumulated amortization	(332.2)	(320.6)
Finite-Lived Intangible Assets, Net	135.9	158.8
Net, indefinite-life intangibles	160.6	163.0
Cost	628.7	642.4
Net	296.5	321.8
Customer relationships
Acquired Intangible Assets By Major Class [Line Items]
Finite-Lived Intangible Assets, Gross	351.2	360.9
Accumulated amortization	(237.7)	(229.9)
Finite-Lived Intangible Assets, Net	113.5	131.0
Trade names intangibles
Acquired Intangible Assets By Major Class [Line Items]
Finite-Lived Intangible Assets, Gross	1.5	1.5
Accumulated amortization	(1.5)	(1.4)
Finite-Lived Intangible Assets, Net	0.0	0.1
Patented Technology [Member]
Acquired Intangible Assets By Major Class [Line Items]
Finite-Lived Intangible Assets, Gross	115.4	117.0
Accumulated amortization	(93.0)	(89.3)
Finite-Lived Intangible Assets, Net	$ 22.4	$ 27.7