Total costs accrued as of the balance sheet date for environmental loss contingencies.

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Amount of expense for newly incurred environmental loss contingencies. Includes, but is not limited to, remediation expense and interest accretion.

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Landfill and Environmental Remediation Liabilities - Changes (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Landfill and environmental remediation liabilities
Interest accretion	$ 24	$ 23
Ending balance, environmental remediation	248
Landfill [Member]
Landfill and environmental remediation liabilities
Beginning balance, landfill	1,855
Obligations incurred and capitalized	20
Obligations settled	(18)
Interest accretion	24
Revisions in estimates and interest rate assumptions	3
Acquisitions, divestitures and other adjustments	(4)
Ending balance, landfill	1,880
Environmental Remediation Liabilities [Member]
Landfill and environmental remediation liabilities
Beginning balance, environmental remediation	240
Obligations settled	(5)
Interest accretion	1
Revisions in estimates and interest rate assumptions	12
Ending balance, environmental remediation	248
Increase (decrease) operating expenses due to change in discount rate	$ 12
Risk-free discount rate of the obligations	0.75%		1.75%