Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 1,258,543	$ 1,343,179	$ 4,040,789	$ 3,677,137
Air traffic liability	429,355		429,355		$ 429,618
DOT—Domestic
Disaggregation of Revenue [Line Items]
Total operating revenues	1,091,157	1,163,193	3,511,446	3,154,984
DOT—Latin America
Disaggregation of Revenue [Line Items]
Total operating revenues	167,386	179,986	529,343	522,153
Total passenger revenues
Disaggregation of Revenue [Line Items]
Total operating revenues	1,233,912	1,322,079	3,971,446	3,619,694
Fare
Disaggregation of Revenue [Line Items]
Total operating revenues	526,776	673,848	1,782,981	1,796,044
Non-fare
Disaggregation of Revenue [Line Items]
Total operating revenues	707,136	648,231	2,188,465	1,823,650
Other
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 24,631	$ 21,100	$ 69,343	$ 57,443