Goodwill and Other Intangibles - Summary of Intangible Assets Acquired (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2021 USD ($)
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Total subject to amortization	$ 225.9
Weighted-average amortization period	24 years
Customer Relationships
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Total subject to amortization	$ 215.4
Weighted-average amortization period	25 years
Trade names
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Total subject to amortization	$ 10.5
Weighted-average amortization period	9 years