Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee.

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Divestitures, Asset Impairments and Unusual Items (Detail) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Asset Impairments and Unusual Items
(Gain) loss from divestitures, asset impairments and unusual items, net	$ 17	$ 61		$ 17	$ 61
Increase in legal accruals	19
Asset impairments	6	61			61
Gain (loss) on sale of assets	$ 8
Refined Coal Facility [Member]
Asset Impairments and Unusual Items
Equity method investments impairment charges			$ 7		7
Landfills and Oil Field Waste Injection Facility [Member]
Asset Impairments and Unusual Items
Asset impairments		41
Asset fair value		8			$ 8
Landfill [Member]
Asset Impairments and Unusual Items
Asset impairments		20
Landfill [Member] \| Carrying Value [Member]
Asset Impairments and Unusual Items
Asset impairments		12
Landfill [Member] \| Expected Timing [Member]
Asset Impairments and Unusual Items
Asset impairments		$ 8