Goodwill and Other Identifiable Intangible Assets - Detail of Identifiable Intangible Assets (Detail) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Acquired Intangible Assets By Major Class [Line Items]
Cost	$ 472.2	$ 433.7
Accumulated amortization	(293.1)	(316.7)
Net	179.1	117.0
Net, indefinite-life intangibles	175.1	159.3
Cost	647.3	593.0
Net	354.2	276.3
Customer relationships
Acquired Intangible Assets By Major Class [Line Items]
Cost	422.6	347.1
Accumulated amortization	(258.3)	(247.9)
Net	164.3	99.2
Trade names intangibles
Acquired Intangible Assets By Major Class [Line Items]
Cost	0.0	0.4
Accumulated amortization	0.0	(0.4)
Net	0.0	0.0
Patented Technology [Member]
Acquired Intangible Assets By Major Class [Line Items]
Cost	49.6	86.2
Accumulated amortization	(34.8)	(68.4)
Net	$ 14.8	$ 17.8