Operating Segments and Related Disclosures - Geographic Revenues (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Total operating revenues	$ 987,556	$ 922,631	$ 859,309	$ 461,279	$ 498,490	$ 401,922	$ 138,529	$ 771,081	$ 3,230,775	$ 1,810,022	$ 3,830,536
DOT—Domestic
Revenues from External Customers and Long-Lived Assets [Line Items]
Total operating revenues									2,824,800	1,660,700	3,462,800
DOT—Latin America and Caribbean
Revenues from External Customers and Long-Lived Assets [Line Items]
Total operating revenues									$ 406,000	$ 149,300	$ 367,700