Property and Equipment, Net - Components of Property and Equipment, Net (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Less: accumulated depreciation	$ (183)	$ (151)
Total property and equipment, net	309	226
Flight equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	344	255
Ground and other equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 148	$ 122