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Financial Instruments - Effect of Net Investment Hedges (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Foreign exchange contracts |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Amount of Pretax (Gain) Loss Recognized in Other Comprehensive Income | $ (18) | $ 0 | $ 2
Foreign exchange contracts | Other (income) expense, net |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Amount of Pretax (Gain) Loss Recognized in Other (income) expense, net for Amounts Excluded from Effectiveness Testing | (11) | 0 | (1)
Euro-denominated notes |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Amount of Pretax (Gain) Loss Recognized in Other Comprehensive Income | (183) | 520 | (193)
Euro-denominated notes | Other (income) expense, net |  |  |
Derivative Instruments and Hedging Activities Disclosures [Line Items] |  |  |
Amount of Pretax (Gain) Loss Recognized in Other (income) expense, net for Amounts Excluded from Effectiveness Testing | $ 0 | $ 0 | $ 0

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- Definition Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), Before Reclassification, Pretax + References No definition available. + Details
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- Definition Other Comprehensive Income (Loss), Net Investment Hedge, Gain (Loss), Reclassification, Pretax + References No definition available. + Details
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