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	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Landfill and environmental remediation liabilities
Interest accretion	$ 47	$ 47
Ending balance, environmental remediation	241
Landfill [Member]
Landfill and environmental remediation liabilities
Beginning balance, landfill	1,760
Obligations incurred and capitalized	36
Obligations settled	(41)
Interest accretion	47
Revisions in estimates and interest rate assumptions	3
Acquisitions, divestitures and other adjustments	5
Ending balance, landfill	1,810
Environmental Remediation Liabilities [Member]
Landfill and environmental remediation liabilities
Beginning balance, environmental remediation	237
Obligations settled	(9)
Interest accretion	3
Revisions in estimates and interest rate assumptions	10
Ending balance, environmental remediation	$ 241
Risk-free discount rate of the obligations	2.00%		2.75%
Increase (decrease) operating expenses due to change in discount rate	$ 8