Leases - Narrative (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) aircraft aircraft_engine	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2023 aircraftLeasebackTransaction	Dec. 31, 2023 aircraft_engine	Dec. 31, 2023 aircraft	Dec. 31, 2023 a	Dec. 31, 2019 USD ($) a residential_building_unit
Lessee, Lease, Description [Line Items]
Number of aircraft unencumbered | aircraft							4
Number of spare engines capitalized | aircraft_engine						28
Number of spare engines capitalized and unencumbered | aircraft_engine						4
Total rental expense	$ 673,200,000	$ 537,900,000	$ 449,400,000
Aircraft rent	$ 381,239,000	$ 282,428,000	$ 246,601,000
Cost, Product and Service [Extensible List]	Aircraft rent	Aircraft rent	Aircraft rent
Supplemental rent expense	$ 14,000,000	$ 16,500,000	$ 31,700,000
Area of land | a								8.5	8.5
Land									$ 41,000,000
Property and equipment		$ 3,749,498,000		$ 3,519,128,000
Operating lease not yet commenced, amount, 2024				3,600,000
Operating lease not yet commenced, amount, 2025 and beyond				0
Third Party Lessor
Lessee, Lease, Description [Line Items]
Number of delivered leased aircraft | aircraft	13
Asset Pledged as Collateral
Lessee, Lease, Description [Line Items]
Number of spare engines capitalized were pledged as collateral | aircraft_engine						24
Aircraft
Lessee, Lease, Description [Line Items]
Failed aircraft sale leaseback					15		15
Construction
Lessee, Lease, Description [Line Items]
Property and equipment				$ 184,600,000
A320 Family
Lessee, Lease, Description [Line Items]
Number of aircraft held | aircraft							205
A320 Family | Aircraft
Lessee, Lease, Description [Line Items]
Number of aircraft owned | aircraft							73
Number of aircraft unencumbered | aircraft							17
Minimum | Aircraft
Lessee, Lease, Description [Line Items]
Finance lease contract term	4 years
Maximum | Aircraft
Lessee, Lease, Description [Line Items]
Finance lease contract term	18 years
Aircraft
Lessee, Lease, Description [Line Items]
Number of aircraft under sale-leaseback transactions | aircraft	10
Aircraft | A320 Family
Lessee, Lease, Description [Line Items]
Number of aircraft under operating lease | aircraft							117
Aircraft | Minimum
Lessee, Lease, Description [Line Items]
Operating lease contract term	4 years
Aircraft | Maximum
Lessee, Lease, Description [Line Items]
Operating lease contract term	18 years
Other
Lessee, Lease, Description [Line Items]
Area of land | a									2.6
Number of residential building unit expected to be built | residential_building_unit									200
Other | Maximum
Lessee, Lease, Description [Line Items]
Operating lease contract term	99 years								99 years
Spare engines
Lessee, Lease, Description [Line Items]
Number of aircraft under operating lease | aircraft_engine						6
Number of engines purchased with cash | aircraft_engine	4
Leased Computer And Office Equipment | Minimum
Lessee, Lease, Description [Line Items]
Finance lease contract term	4 years
Leased Computer And Office Equipment | Maximum
Lessee, Lease, Description [Line Items]
Finance lease contract term	5 years