Other Current Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Other Liabilities Disclosure [Abstract]
Passenger and other taxes and fees payable	$ 141	$ 125
Salaries, wages and benefits	120	107
Station obligations	80	69
Aircraft maintenance	51	76
Fuel liabilities	39	35
Leased aircraft return costs	20	1
Other current liabilities	49	48
Total other current liabilities	$ 500	$ 461