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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
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