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Segments - Additional Information (Detail) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2019 USD ($) Segment	Sep. 30, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | Segment		3
Goodwill, Indefinite-lived and Finite-Lived Intangible and Long-Lived Tangible Assets [Member]
Segment Reporting Information [Line Items]
Charges/ (reversals)		$ 5,385
Inventory Charges [Member]
Segment Reporting Information [Line Items]
Charges/ (reversals)	$ 265	571
Impairment of Long-Lived Tangible Assets [Member]
Segment Reporting Information [Line Items]
Charges/ (reversals)	12
Voluntary Early Retirement Program [Member]
Segment Reporting Information [Line Items]
Charges/ (reversals)		87
Severance, Facility Closures And Other Items [Member]
Segment Reporting Information [Line Items]
Charges/ (reversals)	$ 37	$ 51
Severance, Facility Closures And Reserve Adjustments [Member]
Segment Reporting Information [Line Items]
Charges/ (reversals)			$ (12)

X

- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

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- Definition

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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 5.P.3)
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
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-Subparagraph (SAB Topic 5.P.4(b))
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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