Goodwill and Other Identifiable Intangible Assets - Detail of Identifiable Intangible Assets (Detail) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Acquired Intangible Assets By Major Class [Line Items]
Cost	$ 1,190.5	$ 1,195.9
Accumulated amortization	(413.9)	(405.0)
Net	776.6	790.9
Cost	1,440.1	1,447.4
Net	1,026.2	1,042.4
Customer relationships
Acquired Intangible Assets By Major Class [Line Items]
Cost	1,101.2	1,106.2
Accumulated amortization	(369.5)	(361.8)
Net	731.7	744.4
Other
Acquired Intangible Assets By Major Class [Line Items]
Cost	89.3	89.7
Accumulated amortization	(44.4)	(43.2)
Net	44.9	46.5
Trade names intangibles
Acquired Intangible Assets By Major Class [Line Items]
Net, indefinite-life intangibles	$ 249.6	$ 251.5