Fair Value Measurements - Fair Value Assets and Liabilities Measured on Recurring Basis with Unobservable Inputs (Details) - Fuel derivative contracts $ in Millions	3 Months Ended
	Mar. 31, 2025 USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 130
Total loss for the period
Included in other comprehensive loss	(38)
Ending Balance	92
The amount of total losses for the period included in other comprehensive loss attributable to the change in unrealized gains or losses relating to assets still held as of March 31, 2025	$ 36