Goodwill and Other Identifiable Intangible Assets - Detail of Identifiable Intangible Assets (Detail) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Acquired Intangible Assets By Major Class [Line Items]
Cost	$ 461.7	$ 460.4
Accumulated amortization	(310.4)	(294.6)
Net	151.3	165.8
Net, indefinite-life intangibles	174.1	173.4
Cost	635.8	633.8
Net	325.4	339.2
Customer relationships
Acquired Intangible Assets By Major Class [Line Items]
Cost	419.3	418.1
Accumulated amortization	(283.3)	(269.1)
Net	136.0	149.0
Patented Technology [Member]
Acquired Intangible Assets By Major Class [Line Items]
Cost	42.4	42.3
Accumulated amortization	(27.1)	(25.5)
Net	$ 15.3	$ 16.8