Commitments and Contingencies - Additional Information (Details) $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	Oct. 29, 2024 USD ($)	Sep. 30, 2024 USD ($) employeeGroup	Sep. 30, 2024 USD ($) aircraft employeeGroup engine	Dec. 31, 2023 USD ($)
Long-term Purchase Commitment [Line Items]
Costs capitalized		$ 91	$ 91	$ 78
Litigation settlement, amount awarded from other party		40
Litigation settlement, gain		40
Accounts receivable, net		147	147	93
Legal settlements receivable		$ 40	$ 40
Number of union-represented employee groups | employeeGroup		7	7
Amount of employees represented by unions			87.00%
Accrued liabilities for health care claims		$ 6	$ 6	$ 5
Subsequent Event
Long-term Purchase Commitment [Line Items]
Proceeds from legal settlements	$ 40
Engines
Long-term Purchase Commitment [Line Items]
Number of aircraft agreed to purchase | engine			13
Total Aircraft
Long-term Purchase Commitment [Line Items]
Number of aircraft agreed to purchase | aircraft			193
Total Aircraft | A320neo
Long-term Purchase Commitment [Line Items]
Number of aircraft agreed to purchase | aircraft			27
Total Aircraft | A321neo
Long-term Purchase Commitment [Line Items]
Number of aircraft agreed to purchase | aircraft			166