ACQUISITION OF HAWAIIAN HOLDINGS, INC. - Pro Forma Impact Of Acquisition (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2025	Jun. 30, 2024
Business Combination, Pro Forma Information [Line Items]
Net loss	$ (172)	$ 166	$ (220)	$ 132	$ (6)	$ (88)
Revenue					6,841	6,506
Net income (loss)					$ 72	(96)
Hawaiian Holdings, Inc.
Business Combination, Pro Forma Information [Line Items]
Revenue	3,704		3,629
Net income (loss)	$ 210		$ 171
Hawaiian Holdings, Inc. | Business Combination, Pro Forma Information, Nonrecurring Adjustment, Acquisition-Related Cost
Business Combination, Pro Forma Information [Line Items]
Net loss						$ 320