Landfill and Environmental Remediation Liabilities - Summary (Detail) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Landfill and Environmental Remediation Liabilities
Total, Environmental Remediation	$ 215
Current (in accrued liabilities)	218	$ 231
Long-term	3,132	3,048
Total	3,350	3,279
Landfill [Member]
Landfill and Environmental Remediation Liabilities
Current (in accrued liabilities), Landfill	184	177
Long-term, Landfill	2,951	2,880
Total, Landfill	3,135	3,057
Environmental Remediation Liabilities [Member]
Landfill and Environmental Remediation Liabilities
Current (in accrued liabilities), Environmental Remediation	$ 34	$ 54
Environmental Loss Contingency, Current, Statement of Financial Position [Extensible Enumeration]	Accrued Liabilities, Current	Accrued Liabilities, Current
Long-term, Environmental Remediation	$ 181	$ 168
Environmental Loss Contingency, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Long-term	Long-term
Total, Environmental Remediation	$ 215	$ 222