Commitments and Contingencies - Additional Information (Details) $ in Millions	12 Months Ended
Dec. 31, 2023 USD ($) aircraft employeeGroup	Dec. 31, 2022 USD ($)
Long-term Purchase Commitment [Line Items]
Purchase commitments for aircraft and engines, 2023	$ 1,391
Purchase commitments for aircraft and engines, 2024	2,500
Purchase commitments for aircraft and engines, 2025	2,358
Purchase commitments for aircraft and engines, 2026	2,448
Purchase commitments for aircraft and engines, 2027	2,403
Purchase commitments for aircraft and engines, thereafter	1,356
Future purchase commitments	$ 12,456
Number of union-represented employee groups \| employeeGroup	7
Amount of employees represented by unions	86.00%
Accrued liabilities for health care claims	$ 5	$ 5
Air Transportation Equipment
Long-term Purchase Commitment [Line Items]
Number of aircraft agreed to purchase \| aircraft	210
Air Transportation Equipment \| A320neo
Long-term Purchase Commitment [Line Items]
Number of aircraft agreed to purchase \| aircraft	67
Number of aircraft eligible for conversion \| aircraft	18
Air Transportation Equipment \| A321neo
Long-term Purchase Commitment [Line Items]
Number of aircraft agreed to purchase \| aircraft	143

Long-term Purchase Commitment, Option To Convert Product Type

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- Definition

Multiemployer Plan, Number Of Employee Groups

+ References

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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.

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- Definition

Number of units of goods that must be purchased within the specified time period of the agreement to avoid penalties or unfavorable effects on pricing, among other adverse consequences.

+ References

No definition available.

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- Definition

Percentage of entity's employees covered by collective-bargaining arrangement (CBA) to all entity's employees in multiemployer pension plan determined to be individually significant.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 80
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480576/715-80-50-5

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- Definition

Minimum amount of purchase arrangement in which the entity has agreed to expend funds to procure goods or services from a supplier.

+ References

No definition available.

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- Definition

Amount of purchase arrangement to be paid after fifth fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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Amount of purchase arrangement to be paid in fifth fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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Amount of purchase arrangement to be paid in fourth fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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Amount of purchase arrangement to be paid in next fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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Amount of purchase arrangement to be paid in second fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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Amount of purchase arrangement to be paid in third fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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Carrying amount (including both current and noncurrent portions) of accrued known and estimated losses incurred as of the balance sheet date for which no insurance coverage exists, and for which a claim has been made or is probable of being asserted, typically arising from workmen's compensation-type of incidents and personal injury to nonemployees from accidents on the entity's property.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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