Revenue - Operating Revenue by Geographic Region (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation of Revenue [Line Items]
Operating revenue	$ 12,112	$ 5,471	$ 19,678	$ 8,692
Domestic (U.S. and Canada)
Disaggregation of Revenue [Line Items]
Operating revenue	7,819	3,767	12,905	5,878
Atlantic
Disaggregation of Revenue [Line Items]
Operating revenue	2,481	585	3,570	995
Latin America
Disaggregation of Revenue [Line Items]
Operating revenue	1,195	727	2,104	1,119
Pacific
Disaggregation of Revenue [Line Items]
Operating revenue	$ 617	$ 392	$ 1,099	$ 700