Financial Derivative Instruments - Schedule of (Gain) Loss by Hedging Relationship (Details) - Fuel derivative contracts - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2025 |
Sep. 30, 2024 |
Sep. 30, 2025 |
Sep. 30, 2024 |
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| Designated as Hedging Instrument | ||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| (Gain) loss recognized in AOCI on derivatives, net of tax | $ 0 | $ 61 | $ 69 | $ 83 |
| Not Designated as Hedging Instrument | ||||
| Derivative Instruments, Gain (Loss) [Line Items] | ||||
| (Gain) loss recognized in income on derivatives | $ 0 | $ 29 | $ 0 | $ 31 |
| Derivative, gain (loss), statement of income or comprehensive income [Extensible Enumeration] | Other Nonoperating Income (Expense) | Other Nonoperating Income (Expense) | Other Nonoperating Income (Expense) | Other Nonoperating Income (Expense) |
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- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Indicates line item in statement of income or comprehensive income that includes gain (loss) from derivative. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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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. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount, before tax and reclassification, of gain (loss) from derivative instrument designated and qualifying cash flow hedge included in assessment of hedge effectiveness. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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