Restructuring and Asset Impairment Charges (Narrative) (Details) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2020 USD ($) restructuring_program	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) restructuring_program	Sep. 30, 2019 USD ($)
Restructuring Cost and Reserve
Restructuring costs incurred to date	$ 344		$ 344
Asset impairment charges	$ 10	$ 0	$ 36	$ 0
Closed Restructuring Programs
Restructuring Cost and Reserve
Number of restructuring programs \| restructuring_program	5		5
Restructuring and related activities, number of completed restructuring programs, liability	$ 15		$ 15

Restructuring and Related Activities, Number of Completed Restructuring Programs

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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 costs incurred to date for the specified restructuring cost.

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Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

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