Landfill and Environmental Remediation Liabilities - Summary (Detail) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Landfill and environmental remediation liabilities
Total, Environmental Remediation	$ 241
Current (in accrued liabilities)	151	$ 169
Long-term	1,900	1,828
Total	2,051	1,997
Landfill [Member]
Landfill and environmental remediation liabilities
Current (in accrued liabilities), Landfill	125	143
Long-term, Landfill	1,685	1,617
Total, Landfill	1,810	1,760
Environmental Remediation Liabilities [Member]
Landfill and environmental remediation liabilities
Current (in accrued liabilities), Environmental Remediation	26	26
Long-term, Environmental Remediation	215	211
Total, Environmental Remediation	$ 241	$ 237

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

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