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Commitments and Contingencies - Schedule of Collective Bargaining Agreements (Details) - USD ($) $ in Millions			12 Months Ended
	Dec. 10, 2025	Nov. 07, 2025	Dec. 31, 2025	Dec. 31, 2024
Multiemployer Plan [Line Items]
Amount of employees represented by unions			86.00%
Accrued liabilities for health care claims			$ 7	$ 6
Pilots
Multiemployer Plan [Line Items]
Amount of employees represented by unions			29.00%
Flight Attendants
Multiemployer Plan [Line Items]
Amount of employees represented by unions			48.00%
Aircraft Technicians
Multiemployer Plan [Line Items]
Amount of employees represented by unions			6.00%
Aircraft Appearance Agents
Multiemployer Plan [Line Items]
Amount of employees represented by unions			1.00%
Dispatchers
Multiemployer Plan [Line Items]
Amount of employees represented by unions			1.00%
Material Specialists
Multiemployer Plan [Line Items]
Contract term (in years)		5 years
Maintenance Controllers
Multiemployer Plan [Line Items]
Amount of employees represented by unions			1.00%
Contract term (in years)	5 years

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