Leases (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) aircraft	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Lessee, Lease, Description [Line Items]
Operating lease right-of-use assets	$ 86,727,000	$ 151,928,000
Current maturities of lease liabilities	19,335,000	71,726,000
Noncurrent operating leases	67,392,000	88,622,000
Operating leases	$ 31,700,000
Weighted-average remaining lease term for operating leases	11 years
Weighted-average discount rate for operating leases	6.10%
Lease costs
Operating lease cost	$ 48,169,000	97,998,000	$ 89,891,000
Variable and short-term lease cost	2,840,000	1,830,000	4,468,000
Sublease income	(5,402,000)	(7,089,000)	(6,552,000)
Total lease cost	$ 45,607,000	$ 92,739,000	$ 87,807,000
CRJ Aircraft
Lessee, Lease, Description [Line Items]
Number of aircraft acquired | aircraft	35
Lease liability payable due	$ 142,400,000
Aircraft
Lessee, Lease, Description [Line Items]
Number of aircraft acquired	8
Number of aircraft subleased | aircraft	8
Aircraft | Minimum
Lessee, Lease, Description [Line Items]
Remaining lease term	5 years
Aircraft | Maximum
Lessee, Lease, Description [Line Items]
Remaining lease term	7 years
Airport Facilities | Minimum
Lessee, Lease, Description [Line Items]
Remaining lease term	1 month
Airport Facilities | Maximum
Lessee, Lease, Description [Line Items]
Remaining lease term	33 years