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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Amount of expense (reversal of expense) which increases (decreases) the accrual for environmental loss contingencies from revisions in estimates to existing obligations. Excludes changes related to business acquisitions, divestitures, or currency movement.

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Amount of cash outflow to settle environmental loss contingencies.

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The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

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Landfill and Environmental Remediation Liabilities - Changes (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Landfill and environmental remediation liabilities
Interest accretion		$ 68	$ 67
Ending balance, environmental remediation	$ 250	250
Landfill [Member]
Landfill and environmental remediation liabilities
Beginning balance, landfill		1,576
Obligations incurred and capitalized		51
Obligations settled		(74)
Interest accretion		68
Revisions in estimates and interest rate assumptions		14
Acquisitions, divestitures and other adjustments		5
Ending balance, landfill	1,640	1,640		$ 1,576
Environmental Remediation Liabilities [Member]
Landfill and environmental remediation liabilities
Beginning balance, environmental remediation		246
Obligations settled		(14)
Interest accretion		2
Revisions in estimates and interest rate assumptions		16
Ending balance, environmental remediation	250	250		246
San Jacinto Waste Pits [Member]
Landfill and environmental remediation liabilities
Beginning balance, environmental remediation		46
Revisions in estimates and interest rate assumptions	9	9	$ 42	44
Ending balance, environmental remediation	$ 54	$ 54		$ 46