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Derivatives and Hedging - Narrative (Details) $ in Millions |  | 12 Months Ended
--- | --- | ---
Dec. 31, 2019 USD ($) | Dec. 31, 2019 EUR (€) | Dec. 31, 2020 USD ($) | Dec. 31, 2020 EUR (€) | Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($)
Derivative [Line Items] |  |  |  |  |  |
Estimated pretax losses currently included within Accumulated Other Comprehensive Loss that will be reclassified to earnings in next twelve months |  |  | $ 7 |  |  |
Gain (loss) on derivative |  |  | $ (11) |  | $ (34) | $ (49)
Gross foreign exchange contracts | Not accounted for as hedges |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |
Derivative term of contract |  |  | 90 days | 90 days |  |
Gain (loss) on derivative |  |  | $ 1 |  | (18) | $ 27
Gross foreign exchange contracts | Not accounted for as hedges | Maximum |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |
Derivative term of contract |  |  | 1 year | 1 year |  |
Cash Flow Hedging |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |
Foreign currency exposures, maximum average hedging period (in years) |  |  | 2 years | 2 years |  |
Net Investment Hedging |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |
Outstanding Euro-denominated commercial paper | $ 112 | € 101,000,000 |  | € 0 |  |
Unrealized gain recognized in AOCI |  |  | $ 29 |  | $ 29 |

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