Goodwill and Other Intangible Assets - Schedule of Identifiable Intangible Assets (Detail) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Amortized, Gross Carrying Amount	$ 461.6	$ 488.7
Amortized, Accumulated Amortization	229.2	221.0
Intangible Assets, Gross (Excluding Goodwill)	540.8	568.0
Trademarks [Member]
Indefinite-lived Intangible Assets [Line Items]
Indefinite-Lived, Gross Carrying Amount	79.2	79.3
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Amortized, Gross Carrying Amount	285.3	311.2
Amortized, Accumulated Amortization	141.9	138.0
Existing technology [Member]
Finite-Lived Intangible Assets [Line Items]
Amortized, Gross Carrying Amount	112.5	113.0
Amortized, Accumulated Amortization	41.3	37.5
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Amortized, Gross Carrying Amount	35.4	35.8
Amortized, Accumulated Amortization	22.6	22.3
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Amortized, Gross Carrying Amount	28.4	28.7
Amortized, Accumulated Amortization	$ 23.4	$ 23.2