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Financial Instruments and Fair Value Measurements - Narrative (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2020 | Jun. 30, 2019 | Jun. 30, 2020 | Jun. 30, 2019
Fair Value [Line Items] |  |  |  |
Unrealized gain (loss) on derivative asset |  | $ (4) | $ (24) | $ (1)
Asset-Backed Securities | Minimum |  |  |  |
Fair Value [Line Items] |  |  |  |
Available-for-sale securities remaining maturities |  |  | 1 year |
Asset-Backed Securities | Maximum |  |  |  |
Fair Value [Line Items] |  |  |  |
Available-for-sale securities remaining maturities |  |  | 14 years |
Corporate Debt | Maximum |  |  |  |
Fair Value [Line Items] |  |  |  |
Available-for-sale securities remaining maturities |  |  | 3 years |
U.S. Government and Agency Notes |  |  |  |
Fair Value [Line Items] |  |  |  |
Available-for-sale securities remaining maturities |  |  | 2 years |
Other Fixed-Income Securities |  |  |  |
Fair Value [Line Items] |  |  |  |
Available-for-sale securities remaining maturities |  |  | 1 year |
Azul |  |  |  |
Fair Value [Line Items] |  |  |  |
Equity stake in Azul | 2.00% |  | 2.00% |
Gain (loss) on equity securities | $ 9 | $ 38 | $ (284) | $ 52
Carrying value of investment | $ 101 |  | $ 101 |
Azul | Preferred Stock |  |  |  |
Fair Value [Line Items] |  |  |  |
Equity stake in Azul | 8.00% |  | 8.00% |

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- Definition Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=99377092&loc=SL75136599-209740 + Details
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- Definition The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in earnings for the period. + References Reference 1: 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=121586364&loc=d3e3602-108585 + Details
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