Goodwill and Other Intangible Assets - Summary of Intangible Assets Acquired (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Total subject to amortization	$ 27.7
Weighted-average amortization period	16 years
Total	$ 35.2
Use Rights
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Not subject to amortization	7.5
Customer Relationships
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Total subject to amortization	$ 25.8
Weighted-average amortization period	15 years
Operating Permits
Acquired Finite And Indefinite Lived Intangible Assets [Line Items]
Total subject to amortization	$ 1.9
Weighted-average amortization period	35 years