Leases (Details) $ in Thousands		12 Months Ended
	Jan. 01, 2019 USD ($)	Dec. 31, 2021 USD ($) aircraft	Dec. 31, 2020 USD ($)
Lessee, Lease, Description [Line Items]
Operating lease right-of-use assets		$ 238,516	$ 282,362
Current maturities of lease liabilities		78,886	82,641
Noncurrent operating leases		158,274	205,845
Operating leases		$ 84,700
Weighted-average remaining lease term for operating leases		6 years 3 months 18 days
Weighted-average discount rate for operating leases		6.00%
Lease costs
Operating lease cost		$ 89,891	94,915
Variable and short-term lease cost		4,468	4,619
Sublease income		(6,552)	(6,304)
Total lease cost		87,807	$ 93,230
CRJ 900
Lessee, Lease, Description [Line Items]
Impairment charges		$ 84,592
Aircraft
Lessee, Lease, Description [Line Items]
Number of aircraft acquired | aircraft		43
Impairment charges	$ 13,100
Aircraft | Minimum [Member]
Lessee, Lease, Description [Line Items]
Remaining lease term		2 years
Aircraft | Maximum [Member]
Lessee, Lease, Description [Line Items]
Remaining lease term		9 years
Airport Facilities | Minimum [Member]
Lessee, Lease, Description [Line Items]
Remaining lease term		1 month
Airport Facilities | Maximum [Member]
Lessee, Lease, Description [Line Items]
Remaining lease term		35 years