Landfill and Environmental Remediation Liabilities - Changes (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Landfill and environmental remediation liabilities
Interest accretion	$ 23	$ 22
Ending balance, environmental remediation	251
Landfill [Member]
Landfill and environmental remediation liabilities
Beginning balance, landfill	1,675
Obligations incurred and capitalized	19
Obligations settled	(19)
Interest accretion	23
Revisions in estimates and interest rate assumptions	(9)
Acquisitions, divestitures and other adjustments	12
Ending balance, landfill	1,701
Environmental Remediation Liabilities [Member]
Landfill and environmental remediation liabilities
Beginning balance, environmental remediation	251
Obligations settled	(5)
Interest accretion	1
Revisions in estimates and interest rate assumptions	4
Ending balance, environmental remediation	251
San Jacinto Waste Pits [Member]
Landfill and environmental remediation liabilities
Beginning balance, environmental remediation	55
Ending balance, environmental remediation	$ 55

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

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