Fair Value Measurements and Derivative Instruments - Schedule of Effect of Derivative Instruments Not Designated as Cash Flow Hedging Instruments (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Derivative Instruments | ||||
| Amount of (Loss) Gain Recognized in Income on Derivatives | $ 1 | $ 55 | $ (7) | $ 57 |
| Foreign currency forward contracts | Location, Statement of Income, Balance [Axis]: us-gaap:OtherNonoperatingIncomeExpense | ||||
| Derivative Instruments | ||||
| Amount of (Loss) Gain Recognized in Income on Derivatives | 1 | 53 | (7) | 55 |
| Fuel swaps | Location, Statement of Income, Balance [Axis]: us-gaap:OtherNonoperatingIncomeExpense | ||||
| Derivative Instruments | ||||
| Amount of (Loss) Gain Recognized in Income on Derivatives | $ 0 | $ 2 | $ 0 | $ 2 |