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Financial Derivative Instruments - Premiums for Fuel Derivative Contracts (Details) - Fuel derivatives - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2021 | Mar. 31, 2020
Designated as Hedging Instrument | Operating Expense [Member] |  |
Derivative [Line Items] |  |
Premiums paid for fuel derivative contracts | $ 14 | $ 24
Not Designated as Hedging Instrument | Other (gains)/losses, net |  |
Derivative [Line Items] |  |
Premiums paid for fuel derivative contracts | $ 11 | $ 0

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- Definition The premium (cost) of a hedge, expensed during the period. + References No definition available. + Details
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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. + References No definition available. + Details
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- Details
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- Details
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- Details
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- Details
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