Leases, Commitments, Guarantees and Contingencies (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($) aircraft	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) aircraft	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Lessee, Lease, Description [Line Items]
Operating lease right-of-use assets	$ 85,746		$ 85,746		$ 151,928
Current maturities of lease liabilities	19,225		19,225		71,726
Noncurrent operating leases	$ 66,520		66,520		$ 88,622
Operating leases			$ 26,200
Weighted-average remaining lease term for operating leases	10 years		10 years
Weighted-average discount rate for operating leases	6.10%		6.10%
Lease costs
Operating lease cost	$ 7,959	$ 21,697	$ 40,764	$ 65,360
Variable and short-term lease cost	868	765	2,205	2,588
Sublease income	(1,350)	(1,845)	(4,051)	(5,492)
Total lease cost	$ 7,477	$ 20,617	$ 38,918	$ 62,456
CRJ Aircraft
Lessee, Lease, Description [Line Items]
Number of aircraft acquired | aircraft	3		35
Lease liability payable due	$ 142,400		$ 142,400
Aircraft
Lessee, Lease, Description [Line Items]
Number of aircraft acquired | aircraft			8
Aircraft | Minimum
Lessee, Lease, Description [Line Items]
Remaining lease term	6 years		6 years
Aircraft | Maximum
Lessee, Lease, Description [Line Items]
Remaining lease term	7 years		7 years
Airport Facilities | Minimum
Lessee, Lease, Description [Line Items]
Remaining lease term	1 month		1 month
Airport Facilities | Maximum
Lessee, Lease, Description [Line Items]
Remaining lease term	33 years		33 years