Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 1,280,889	$ 1,432,472	$ 2,546,426	$ 2,782,246
Air traffic liability	496,985		496,985		$ 383,751
DOT—Domestic
Disaggregation of Revenue [Line Items]
Total operating revenues	1,141,272	1,244,818	2,235,762	2,420,554
DOT—Latin America
Disaggregation of Revenue [Line Items]
Total operating revenues	139,617	187,654	310,664	361,692
Total passenger revenues
Disaggregation of Revenue [Line Items]
Total operating revenues	1,253,803	1,410,061	2,493,113	2,737,534
Fare
Disaggregation of Revenue [Line Items]
Total operating revenues	531,652	647,344	1,051,594	1,256,205
Non-fare
Disaggregation of Revenue [Line Items]
Total operating revenues	722,151	762,717	1,441,519	1,481,329
Other
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 27,086	$ 22,411	$ 53,313	$ 44,712