Restructuring and Other Charges - Schedule of Restructuring and Other Charges (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring and Related Activities [Abstract]
Layoff costs	$ 113	$ 69	$ 18
Reversals of and adjustments to previously recorded layoff reserves	(21)	(6)	(8)
Pension, Other post-retirement benefits (costs) and deferred compensation - net settlement and curtailments	69	(7)	91
Non-cash asset impairments (O)	5	442	9
Net loss on divestitures of assets and businesses (U)	8	63	43
Other	8	21	10
Restructuring and other charges	$ 182	$ 582	$ 163

Other costs related to restructuring.

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Reversals of previously recorded layoff.

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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) from sale and disposal of integrated set of activities and assets capable of being conducted and managed for purpose of providing return in form of dividend, lower cost, or other economic benefit to investor, owner, member and participant.

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Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

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