Goodwill and Intangible Assets - Summary of Intangible Assets (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Finite Lived Intangible Assets [Line Items]
Amortizable intangible assets		$ 1,093.6	$ 1,093.5	$ 1,086.2
Accumulated amortization		(703.8)	(682.3)	(631.0)
Total amortizable intangible assets, net		389.8	411.2	455.2
Indefinite-lived trademarks		9.8	9.8	9.8
Total intangibles, net		$ 399.6	421.0	465.0
Weighted Average [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	[1]	15 years 3 months 18 days
Noncompete Agreements [Member]
Finite Lived Intangible Assets [Line Items]
Amortizable intangible assets		$ 0.2	0.2	0.2
Noncompete Agreements [Member] | Weighted Average [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	[1]	2 months 12 days
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Amortizable intangible assets		$ 1,092.4	1,092.3	$ 1,086.0
Customer Relationships [Member] | Weighted Average [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	[1]	15 years 3 months 18 days
Trademarks [Member]
Finite Lived Intangible Assets [Line Items]
Amortizable intangible assets		$ 1.0	$ 1.0
Trademarks [Member] | Weighted Average [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	[1]	1 year 7 months 6 days

[1] As of March 31, 2022.