Fair Value Measurements and Derivative Instruments (Derivatives Not Designated as Hedging Instruments) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Derivative instruments disclosure
Amount of Gain (Loss) Recognized in Income on Derivative	$ 20	$ (102)	$ 3
Foreign currency forward contracts | Other (expense) income
Derivative instruments disclosure
Amount of Gain (Loss) Recognized in Income on Derivative	19	(102)	(31)
Fuel swaps | Other (expense) income
Derivative instruments disclosure
Amount of Gain (Loss) Recognized in Income on Derivative	$ 1	$ 0	$ 34