Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2022

Fair Value Disclosures [Abstract]

Schedule of assets (liabilities) measured at fair value on a recurring basis

Assets/(Liabilities) Measured at Fair Value on a Recurring Basis

(in millions)	March 31, 2022		Level 1		Level 2		Level 3
Cash equivalents	$	5,132	$	5,132	$	—	$	—
Restricted cash equivalents	429		429		—		—
Short-term investments	2,250		681		1,569		—
Long-term investments	1,312		1,179		36		97
Fuel hedge contracts	(14)		—		(14)		—

(in millions)	December 31, 2021		Level 1		Level 2		Level 3
Cash equivalents	$	5,450	$	5,450	$	—	$	—
Restricted cash equivalents	635		635		—		—
Short-term investments	3,386		1,376		2,010		—
Long-term investments	1,459		1,326		36		97
Fuel hedge contracts	(18)		—		(18)		—