Other Current Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Other Liabilities Disclosure [Abstract]
Salaries, wages and benefits	$ 89	$ 97
Passenger and other taxes and fees payable	84	41
Station obligations	64	33
Aircraft maintenance	36	22
Current portion of phantom equity units	26	0
Leased aircraft return costs	25	20
Fuel liabilities	23	6
Warrant liability	0	18
Other current liabilities	36	30
Total other current liabilities	$ 383	$ 267