Summary of Significant Accounting Policies - Landfill (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($) item site	Dec. 31, 2023 USD ($)	Dec. 31, 2022
Significant accounting policies
Expansion landfill sites requiring CFO approval, unpermitted airspace | item	1
Range of loss not accrued	$ 9
Environmental remediation liabilities	$ 222
Landfill [Member]
Significant accounting policies
Inflation rate	2.50%	2.50%	2.50%
Environmental remediation accrual discount rate (as a percent)	4.80%
Landfills sites with expansion | site	18
Landfill [Member] | Minimum [Member]
Significant accounting policies
Permit application process period	1 year
Landfill [Member] | Maximum [Member]
Significant accounting policies
Permit application process period	5 years
Environmental Remediation Liabilities [Member]
Significant accounting policies
Environmental remediation liabilities	$ 222	$ 209