Fair Value Measurements and Derivative Instruments - Schedule of Designated Cash Flow Hedges (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Effect of derivative instruments involved in hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Loss on Derivatives	$ 56	$ (31)
Interest rate swaps
Effect of derivative instruments involved in hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Loss on Derivatives	21	(11)
Foreign currency forward contracts
Effect of derivative instruments involved in hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Loss on Derivatives	(71)	21
Fuel swaps
Effect of derivative instruments involved in hedging on the consolidated financial statements
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Loss on Derivatives	$ 106	$ (41)