Other Current Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Other Liabilities Disclosure [Abstract]
Passenger and other taxes and fees payable	$ 99	$ 84
Salaries, wages and benefits	84	89
Station obligations	57	64
Aircraft maintenance	50	36
Fuel liabilities	33	23
Leased aircraft return costs	24	25
Current portion of phantom equity units	0	26
Other current liabilities	40	36
Total other current liabilities	$ 387	$ 383