Financial Derivative Instruments - Premiums for Fuel Derivative Contracts (Details) - Fuel derivative contracts - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Designated as Hedging Instrument \| Fuel and oil
Derivative [Line Items]
Premium expense (benefit) recognized in income on derivatives	$ 40	$ 30	$ 79	$ 61
Not Designated as Hedging Instrument \| Other (gains)/losses, net
Derivative [Line Items]
Premium expense (benefit) recognized in income on derivatives	$ (1)	$ 0	$ (1)	$ 0

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
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480237/815-40-50-5

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Balance Type:	na
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