Landfill and Environmental Remediation Liabilities - Changes to Landfill and Environmental Remediation Liabilities (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Environmental Exit Cost [Line Items]
Interest accretion	$ 22	$ 21
Ending balance, environmental remediation	207
Landfill [Member]
Environmental Exit Cost [Line Items]
Beginning balance, landfill	1,518
Obligations incurred and capitalized	13
Obligations settled	(15)
Interest accretion	22
Revisions in estimates and interest rate assumptions	(1)
Acquisitions, divestitures and other adjustments	4
Ending balance, landfill	1,541
Environmental Remediation Liabilities [Member]
Environmental Exit Cost [Line Items]
Beginning balance, environmental remediation	209
Obligations settled	(5)
Interest accretion	1
Revisions in estimates and interest rate assumptions	2
Acquisitions, divestitures and other adjustments	0
Ending balance, environmental remediation	$ 207

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

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