Commitments, Contingencies and Other Contractual Arrangements - Employees (Details) $ in Millions			2 Months Ended	3 Months Ended	9 Months Ended
	Nov. 01, 2025 flightAttendant	Oct. 01, 2025 pilot	Mar. 12, 2025 USD ($) employee pilot	Sep. 30, 2025 USD ($) employeeGroup employee	Sep. 30, 2025 employeeGroup employee	Nov. 06, 2025 agreement
Concentration Risk [Line Items]
Number of pilots furloughed (approximately)			200
Furlough expenses | $			$ 0.9	$ 3.6
Number of positions eliminated from various departments (approximately) | employee			200
Expenses related to eliminated positions | $			$ 1.8
Subsequent Event
Concentration Risk [Line Items]
Agreements in principle reached, number of unions | agreement						2
Number of pilots furloughed (approximately)		270
Number of pilots downgraded during period (approximately)		140
Number of flight attendants furloughed during period (approximately) | flightAttendant	1,800,000
Aircraft Mechanics Fraternal Association ("AMFA")
Concentration Risk [Line Items]
Number of employees included in union application (approximately) | employee				532	532
Number of Employees, Total | Unionized Employees Concentration Risk
Concentration Risk [Line Items]
Number of union-represented employee groups | employeeGroup				6	6
Company's employees covered under collective bargaining agreements percentage					83.00%
Number of Employees, Total | Unionized Employees Concentration Risk | Air Line Pilots Association, International ("ALPA") (2)
Concentration Risk [Line Items]
Company's employees covered under collective bargaining agreements percentage					26.00%
Number of Employees, Total | Unionized Employees Concentration Risk | Association of Flight Attendants ("AFA-CWA")
Concentration Risk [Line Items]
Company's employees covered under collective bargaining agreements percentage					45.00%
Number of Employees, Total | Unionized Employees Concentration Risk | Professional Airline Flight Control Association ("PAFCA")
Concentration Risk [Line Items]
Company's employees covered under collective bargaining agreements percentage					1.00%
Number of Employees, Total | Unionized Employees Concentration Risk | International Association of Machinists and Aerospace Workers ("IAMAW")
Concentration Risk [Line Items]
Company's employees covered under collective bargaining agreements percentage					3.00%
Number of Employees, Total | Unionized Employees Concentration Risk | Transport Workers Union of America ("TWU")
Concentration Risk [Line Items]
Company's employees covered under collective bargaining agreements percentage					3.00%
Number of Employees, Total | Unionized Employees Concentration Risk | Aircraft Mechanics Fraternal Association ("AMFA")
Concentration Risk [Line Items]
Company's employees covered under collective bargaining agreements percentage					5.00%