Goodwill and Other Identifiable Intangible Assets - Identifiable Intangible Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Acquired Intangible Assets by Major Class [Line Items]
Finite-life intangibles, cost	$ 1,647.3	$ 1,621.1
Accumulated amortization	(533.1)	(448.4)
Finite-life intangibles, net	1,114.2	1,172.7
Indefinite-life intangibles	444.2	459.1
Total intangibles, cost	2,091.5	2,080.2
Total intangibles, net	1,558.4	1,631.8
Customer relationships
Acquired Intangible Assets by Major Class [Line Items]
Finite-life intangibles, cost	1,513.9	1,478.0
Accumulated amortization	(437.5)	(346.7)
Finite-life intangibles, net	1,076.4	1,131.3
Trade names
Acquired Intangible Assets by Major Class [Line Items]
Finite-life intangibles, cost	1.5	1.8
Accumulated amortization	(1.4)	(1.4)
Finite-life intangibles, net	0.1	0.4
Patented Technology [Member]
Acquired Intangible Assets by Major Class [Line Items]
Finite-life intangibles, cost	131.9	141.3
Accumulated amortization	(94.2)	(100.3)
Finite-life intangibles, net	$ 37.7	$ 41.0