Goodwill and Other Identifiable Intangible Assets - Detail of Identifiable Intangible Assets (Detail) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Acquired Intangible Assets By Major Class [Line Items]
Cost	$ 1,186.9	$ 1,204.6
Accumulated amortization	(383.4)	(358.9)
Net	803.5	845.7
Cost	1,435.1	1,453.5
Net	1,051.7	1,094.6
Customer relationships
Acquired Intangible Assets By Major Class [Line Items]
Cost	1,097.9	1,100.9
Accumulated amortization	(342.5)	(308.9)
Net	755.4	792.0
Other
Acquired Intangible Assets By Major Class [Line Items]
Cost	89.0	89.3
Accumulated amortization	(40.9)	(35.6)
Net	48.1	53.7
Trade names intangibles
Acquired Intangible Assets By Major Class [Line Items]
Net, indefinite-life intangibles	248.2	248.9
Other Intangible Assets
Acquired Intangible Assets By Major Class [Line Items]
Cost	0.0	14.4
Accumulated amortization	0.0	(14.4)
Net	$ 0.0	$ 0.0