Goodwill and Other Identifiable Intangible Assets - Detail of Identifiable Intangible Assets (Detail) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Acquired Intangible Assets By Major Class [Line Items]
Cost	$ 1,152.9	$ 1,235.3
Accumulated amortization	(380.0)	(448.6)
Net	772.9	786.7
Cost	1,402.5	1,482.4
Net	1,022.5	1,033.8
Customer relationships
Acquired Intangible Assets By Major Class [Line Items]
Cost	1,077.7	1,146.5
Accumulated amortization	(343.9)	(400.2)
Net	733.8	746.3
Other
Acquired Intangible Assets By Major Class [Line Items]
Cost	75.2	88.8
Accumulated amortization	(36.1)	(48.4)
Net	39.1	40.4
Trade names intangibles
Acquired Intangible Assets By Major Class [Line Items]
Net, indefinite-life intangibles	$ 249.6	$ 247.1