Intangible Assets, net - Summary of Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	$ 26	$ 26
Amortization Period	16 years
Finite-lived intangible assets, Gross Carrying Amount	$ 16	16
Finite-lived intangible assets, Accumulated Amortization	(14)	(14)
Finite-lived intangible assets, net, total	2	2
Total intangible assets, net, Gross Carrying Amount	42	42
Intangible assets, net	28	28
Airport slots
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	20	20
Trademarks
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	$ 6	$ 6