Goodwill and Other Identifiable Intangible Assets - Detail of Identifiable Intangible Assets (Detail) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Acquired Intangible Assets By Major Class [Line Items]
Cost	$ 1,190.1	$ 1,195.9
Accumulated amortization	(426.8)	(405.0)
Net	763.3	790.9
Cost	1,439.2	1,447.4
Net	1,012.4	1,042.4
Customer relationships
Acquired Intangible Assets By Major Class [Line Items]
Cost	1,100.8	1,106.2
Accumulated amortization	(381.0)	(361.8)
Net	719.8	744.4
Other
Acquired Intangible Assets By Major Class [Line Items]
Cost	89.3	89.7
Accumulated amortization	(45.8)	(43.2)
Net	43.5	46.5
Trade names intangibles
Acquired Intangible Assets By Major Class [Line Items]
Net, indefinite-life intangibles	$ 249.1	$ 251.5